Ecological,Wetland

Have you heard the term 'watershed' but never actually had it explained to you? Fortunately, explaining a watershed is pretty easy, and the importance of watersheds can't really be overstated. Here, I'll try to explain watersheds using interesting examples and stories from around the world.

Before we dive in, the definition of a watershed on the <a href="https://oceanservice.noaa.gov/facts/watershed.html" target="_blank" rel="noopener noreferrer">National Oceanic and Atmospheric Administration's website</a> is "a land area that channels rainfall and snowmelt to creeks, streams, and rivers, and eventually to outflow points such as reservoirs, bays, and the ocean."
<h2>Explaining Watershed Basics</h2>
[caption id="attachment_1884610" align="alignnone" width="747"]<img class="wp-image-1884610 size-full" src="https://www.earth.com/wp-content/uploads/2020/10/1024px-Casiquiarerivermap.png" alt="watershed map" width="747" height="747" /> A map of the Amazon River watershed. The area highlighted in yellow all drains towards the Amazon River. Thus, that is the Amazon watershed. Map by <a href="https://en.wikipedia.org/wiki/User:Kmusser?rdfrom=commons:User:Kmusser" target="_blank" rel="noopener noreferrer">Karl Musser</a> via <a href="https://commons.wikimedia.org/wiki/File:Casiquiarerivermap.png" target="_blank" rel="noopener noreferrer">Wikimedia</a>[/caption]
<h3>1. The Amazon River Versus Your Local Stream - Watersheds Come In All Sizes</h3>
The Amazon watershed is the largest in the world, spanning some four million square kilometers. The map above shows all of the lands that drain into the Amazon River. The water in the Amazon River comes from Bolivia, Peru, Ecuador, Colombia, Venezuela, and Brazil. All of these countries are part of the Amazon watershed.

The large rivers that feed directly into the Amazon, such as the Madeira and the Negro, are major tributaries to the Amazon. The Cassiquiare (highlighted in purple) is a minor tributary. Each of these smaller rivers has its own watershed, which is nested within the Amazon watershed.

As opposed to the Amazon, watersheds can also be small, such as an alpine mountain bowl. Since the water in the mountain bowl will connect with another stream in a short distance, that one alpine bowl is the entire watershed for that stream. Sometimes you can see an entire watershed at once if you are in the right place and it is a small watershed.

As a side note, watershed maps can make some pretty stunning visuals.

[caption id="attachment_1884609" align="alignnone" width="540"]<img class="wp-image-1884609 size-full" src="https://www.earth.com/wp-content/uploads/2020/10/NorthAmericaDivides.gif" alt="continetal divides" width="540" height="481" /> A map of the continental divides in North America. Triple Divide Peak is where the green and red lines intersect. Map by <a href="https://en.wikipedia.org/wiki/National_Atlas_of_the_United_States" target="_blank" rel="noopener noreferrer">National Atlas of the U.S.</a> via <a href="https://commons.wikimedia.org/wiki/File:NorthAmericaDivides.gif" target="_blank" rel="noopener noreferrer">Wikimedia</a>[/caption]
<h3>2. Triple Divide Peak - The Concept of Continental Divides</h3>
A continental divide is a high point that determines where water goes. If water falls on the left side of the Great Divide (red line) it flows to the Pacific Ocean. If it falls on the right side, it goes to the Gulf of Mexico.

Triple Divide Peak in Glacier National Park is a very interesting place with regards to watersheds. The peak is where the green and red lines meet on the map. Instead of a normal divide, this peak is the intersection of two continental divides. This means that a storm that hits Triple Divide Peak will send water to the Pacific Ocean, Gulf of Mexico, and the Arctic Ocean all at once! That same storm will send water to the swamps of Louisiana and the icebergs of Canada.

Continental Divides are the largest of divides, but any ridge that separates two watersheds is considered a divide. As with watersheds, divides can be huge or small.

<img class="wp-image-1884605 size-full" src="https://www.earth.com/wp-content/uploads/2020/10/P1040092-1.jpg" alt="arctic watershed" width="1020" height="766" />

An example of a watershed meeting the ocean in arctic Alaska. Photo by the author.
<h3>3. Tracking Pollution - How Tributaries Work</h3>
A watershed is made up of many tributaries, as described above. Imagine researchers in New Orleans (the end of the Mississippi watershed) noticed new oil pollution occurring in the Mississippi River. They can track down the source of that pollution by working backstream up to the source of oil pollution.

Since smaller tributaries flow into larger ones, the concentration of oil in the tributaries closer to the oil pollution will be higher. As the oil flows away from the pollution source, it gets diluted.

Say the researchers work upstream and get to the confluence (meeting point) of the Mississippi and Arkansas rivers. They notice most of the oil is coming from the Arkansas River, a major tributary of the Mississippi, so they work up that river until they find the next tributary contributing large amounts of oil. As they work up the tributaries, the concentration of oil in the water will increase and the researchers will likely find the culprits of the pollution. This is one way to find polluters using a watershed. It also demonstrates how tributaries work.

In a real-world example, in the Alaskan arctic, increasing wildfires due to climate change have altered the composition of rivers. The <a href="https://www.earth.com/news/wildfires-alter-the-composition-of-arctic-watersheds-for-50-years/" target="_blank" rel="noopener noreferrer">rivers now contain more carbon and nitrogen</a> from ash due to the fires than they previously did.
<h3>4. The Unpredictable Colorado River - Watersheds Change Throughout the Year</h3>
Before humans put a series of dams on it, the Colorado River was the most dynamic river in the world. The Colorado River is fed primarily by Colorado, Wyoming, and Utah. Much of the flow comes from melting winter snowpack in those states. When almost all of the snow has melted in the late summer, there is very little water feeding the river.

Historically, the Colorado River, which <a href="https://www.usgs.gov/mission-areas/water-resources/science/colorado-river-basin-focus-area-study?qt-science_center_objects=0#" target="_blank" rel="noopener noreferrer">drains about 1/12th</a> of the continental U.S., could run as little more than a small stream in the deep summer of a dry year. Conversely, on a big snow year, and with strong summer monsoons, the Colorado River could reach <a href="http://classes.colgate.edu/rturner/econ326/Glen%20Canyon%20Dam/Default.htm" target="_blank" rel="noopener noreferrer">500,00 cubic feet per second (cfs)</a>, pushing nearly as much water as the Mississippi. By contrast, the historical annual average for the river is about 22,500 cfs. This shows that rivers can change dramatically based on what happens in their watersheds.
<h3>5. The Great Basin - Sometimes Watersheds Don't Reach the Ocean</h3>
The Great Basin covers almost all of Nevada and some of its surrounding states (see in the continental divide map above). This area is defined by being an endorheic basin, which means that none of the rain or snow that falls within the basin makes it to the ocean.

Instead of a normal watershed that flows to the ocean, the Great Basin is like an enormous bowl. All precipitation that falls above the bowl drains to the bottom of the bowl. All the precipitation that falls outside the bowl makes it to the Pacific Ocean. In this analogy, the rim of the bowl represents the continental divide between the Great Basin and the Pacific Ocean.

You may be wondering "if the water doesn't drain out to the ocean, where does it go?"

In some cases, it collects in lakes, such as Pyramid Lake, Lake Tahoe, or <a href="https://www.earth.com/news/127991/" target="_blank" rel="noopener noreferrer">Great Salt Lake</a>. In other cases, it simply drains down into the earth through cracks in the rocks. Over millions of years, water that seeps through the rocks creates an aquifer. An aquifer is a massive underground reservoir of water.

While the idea of an endorheic basin might seem unlikely, they <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6267997/" target="_blank" rel="noopener noreferrer">actually cover 20% </a>of the Earth's land area. Most of the interior of Asia is actually an endorheic basin!

[caption id="attachment_1884603" align="alignnone" width="638"]<img class="wp-image-1884603 size-full" src="https://www.earth.com/wp-content/uploads/2020/10/P1060152-1.jpg" alt="endorheic watershed" width="638" height="479" /> These lakes flow into the valley far off. The valley is an endorheic basin, meaning the water doesn't flow to the ocean. Rather, it seeps belowground into an aquifer. Photo by the author.[/caption]
<h2>Explaining Watersheds and the Environment</h2>
<h3>5. Salmon Runs in the Elwha - Watersheds Indicate Environmental Health</h3>
As noted above with the pollution example, watersheds can tell us valuable information about our landscapes. Take the Elwha River in Olympic National Park, for example. In 2011, the national park began the largest dam removal in history. They took down two dams on the Elwah River, which had blocked salmon from spawning upstream for nearly 100 years.

From the perspective of a salmon, a watershed with lots of dams is not a good watershed. While salmon are impressive jumpers, they can't jump over dams 100 feet high. Since they need to head upriver to lay eggs, dams around the world prevent salmon from reproducing.

However, just a few years after the Elwah dams disappeared, the salmon came back in force. In the years since the removal, <a href="https://www.peninsuladailynews.com/sports/outdoors-elwha-river-summer-steelhead-on-the-rebound/" target="_blank" rel="noopener noreferrer">steady salmon runs</a> have developed on the Elwah River.

The Elwah watershed is almost entirely within the national park, meaning it doesn't have many other environmental pressures such as human development or pollution. So when the dams came down, there was little preventing the salmon from recolonizing their historical homes.

This example of watershed restoration shows how the watershed's health can be an indication of an entire ecosystem's health. Since the Olympics are relatively pristine, the salmon easily retook their habitat. However, if humans took dams down along a heavily polluted river with many major cities on it, it would be harder for the salmon to retake.

[caption id="attachment_1884606" align="alignnone" width="479"]<img class="wp-image-1884606 size-full" src="https://www.earth.com/wp-content/uploads/2020/10/P1050099-1.jpg" alt="the grand canyon, a dramatic watershed" width="479" height="638" /> The Colorado River in the Grand Canyon. Photo by the author.[/caption]
<h3>6. The Colorado Pikeminnow - A Species That Exists in Just One Watershed</h3>
Imagine you are a fish in a river. It would be pretty difficult to move to a different river altogether, right? Watersheds often have fish, amphibians, and insects that are unique to that river system for precisely this reason.

The Colorado pikeminnow is an example of this specialization. Living only in the Colorado River, this fish is a minnow that grows <a href="https://www.coloradoriverrecovery.org/general-information/the-fish/colorado-pikeminnow.html" target="_blank" rel="noopener noreferrer">up to six feet long</a>! If you think this is strange, well, it is. Minnows are generally small. However, this minnow was isolated from other watersheds for so long that it changed into something completely different - the top predator of an entire river system! Watersheds can determine the evolutionary fate of species such as the Colorado pikeminnow.

Unfortunately, all the dams, human development, and invasive species in the Colorado River, the pikeminnow is a federally endangered species.
<h3>7. Airsheds and Foodsheds - The Concept of Watersheds Broadens</h3>
Now that we have explained watersheds, perhaps we should explore other 'sheds.'

Airsheds are defined by regions that share the same air quality. If a coal-fired powerplant is in your airshed, it will pollute your air, just as if someone dumped pollution upstream in your watershed, it would impact you downstream. Unlike watersheds, which always have movement from upstream to downstream, the movement in an airshed changes depending on the season, weather, and climate of that airshed.

Foodsheds are less geographically determined than airsheds and watersheds and are created more by humans. <a href="https://www.canr.msu.edu/news/what_is_a_food_shed" target="_blank" rel="noopener noreferrer">A foodshed</a> is a geographic area that grows food for consumers in that area. Foodsheds are a central concept to the local food movement.

[caption id="attachment_1884602" align="alignnone" width="956"]<img class="wp-image-1884602 size-full" src="https://www.earth.com/wp-content/uploads/2020/10/P1040263-1.jpg" alt="watersheds" width="956" height="719" /> All of the fresh snow is part of this watershed. The snow will melt into the river, which drains to the ocean. Photo by the author.[/caption]
<h2>Explaining Watersheds and How they Relate to the Law</h2>
<h3></h3>
<h3>8. The California Aquaduct - Watersheds Create Fights</h3>
"Whiskey is for drinking, water is for fighting" is a common phrase heard around the West. And it's true. The western U.S. is severely prone to droughts, which are worsened by climate change. As a result, places like Arizona and southern California have used all of their natural water. To overcome their lack of water, western states have engaged in feats of great engineering involving pumps, aqueducts, tunnels, and dams. Some aqueducts move water from one watershed to another, through mountains and across plains.

The California aqueduct is one such aqueduct. It moves water that originates in far northern California and pumps it as far south as L.A. The water crosses multiple watersheds in a completely unnatural system. Literal cubic miles of water are pushed up thousands of feet to make it from north to south, requiring tremendous amounts of energy.

While some in California see this distribution of water as equitable, others say its wrong to move water outside of its original watershed.

Legal questions regarding how water can be distributed are ongoing. In Nevada, it is illegal to move water from one basin to another. However, Las Vegas has tried for 30 years to do just that. After seven failed lawsuits, the Southern Nevada Water Authority <a href="https://www.hcn.org/issues/52.10/south-water-killing-the-vegas-pipeline" target="_blank" rel="noopener noreferrer">gave up the potential project</a>, which would pump an aquifer in the northeast of the state and bring it to Las Vegas through a pipeline.
<h3>9. The Whanganui River is a Legal Person - Watersheds Gain Rights</h3>
Some environmental lawyers and indigenous groups have found success in getting watersheds the rights of a legal person. The first such case was in New Zealand, where the Whanganui River gained rights in 2017. This means that lawyers sue on behalf of the river, charging that activities such as pollution or development harm the natural state of the river and that actions must be taken to restore that natural state.

While it may seem bizarre to categorize a river as a 'legal person,' it isn't so unusual. Corporations are legal people in the U.S., enjoying more rights than almost all animals and natural places. Many environmental lawyers believe that watersheds deserve that same personhood.

The Yurok tribe in northern California followed suit a few years after New Zealand and succeeded in getting the <a href="https://www.hcn.org/issues/51.18/tribal-affairs-the-klamath-river-now-has-the-legal-rights-of-a-person#:~:text=The%20Klamath%20River%20runs%20through,same%20rights%20as%20a%20person.&amp;text=In%20essence%2C%20the%20Yurok%20resolution,court%20to%20remedy%20the%20problem." target="_blank" rel="noopener noreferrer">Klamath River designated as a legal person</a>. This includes all of the tributaries within the watershed of the Klamath. This case is particularly interesting because a larger dam removal project than that on the Elwah will occur on the Klamath in the next few years.

I encourage you to learn more about your own watershed. We all have one and we would all benefit by knowing a little more about the resources that give us life.

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Explaining Watersheds with 9 Examples

Have you heard the term 'watershed' but never actually had...

Pile,Of,Colorful,Blankets,Made,From,Fleece,,All,Rolled,Up.

Since outdoor clothing brand Patagonia introduced fleece in the early 1980s, it’s become a wardrobe staple for nature lovers across the globe. But the light, breathable fleece microfibers aren't as environmentally friendly as its fan-base might suggest. 

It’s made from synthetic textiles -- specifically polyester, acrylic, and nylon -- and in a single washing machine cycle, fleece can shed hundreds of thousands of tiny plastic particles known as microfibers. 

These microfibers contribute to global plastic pollution and can harm both marine organisms and the humans who eat them. 

Before we go any further, let’s cover what exactly microfibers are and how they travel from our fleece sweaters into the bellies of fish.

<img class="alignnone wp-image-1872025 size-full" src="https://www.earth.com/wp-content/uploads/2019/05/fleece-233768_960_720.jpg" alt="fleece microfiber plastic pollution" width="960" height="639" />
<h2>What Are Microfibers? </h2>
Microfibers are a subgroup of microplastics -- pieces of plastic typically defined as smaller than five millimeters (even thinner than a strand of hair) and composed of various synthetic polymers.

The water from washing machines takes microfibers down the drain, through wastewater treatment plants (which are unable to filter out 40 percent of all microfibers), and eventually into rivers, lakes, and oceans.
<h2>How Are Microfibers Harmful to the Environment?</h2>
It’s clear the accumulation of plastic in surface waters is detrimental to the environment. But since they’re not visible to the naked eye, it’s easy to underestimate the power of microfiber accumulation. According to a 2011 study, <a href="https://www.earth.com/news/clothes-dryers-release-millions-of-microfibers-into-the-air/" target="_blank" rel="noopener">microfibers</a> make up the majority of human-made debris on shorelines around the world.

Because they’re so small and pervasive in our oceans, microfibers can easily be consumed by fish and other marine wildlife. 

Though the effects of this consumption are still being determined, research shows that ingesting microfibers decreases the appetites of <a href="https://pubs.acs.org/doi/abs/10.1021/acs.est.5b04026?journalCode=esthag" target="_blank" rel="noopener">Carcinus maenas (crabs)</a> and increases the mortality of Daphnia magna (water fleas).

In <a href="https://www.chicagotribune.com/news/local/breaking/chi-great-lakes-plastic-fibers-scientists-20150109-story.html" target="_blank" rel="noopener">a 2015 interview with the Chicago Tribune</a>, chemist Sherri Mason said that in her research studying microscopic litter in the Great Lakes, she found that while other kinds of microplastic were able to be excreted by fish, she’d seen microfibers laced through their gastrointestinal tracts. 

"The longer the plastic remains inside an organism,” Mason explained, “the greater the likelihood that it will impact the organism in some way."
<h2>How Are Fleece Microfibers Harmful to Humans? </h2>
Although some doubt that humans ingest or are affected by these smaller organisms’ ingestion of microfibers, toxic chemicals in microfibers could bioaccumulate in the sea creatures we eat and ultimately negatively impact human health. 

However, the problem extends beyond our seafood: microplastics have been <a href="https://pubs.acs.org/doi/abs/10.1021/acs.est.5b03163" target="_blank" rel="noopener">found in table salt in China</a>, and in tap water all over the world. 

The US has the highest tap water contamination rate -- <a href="https://orbmedia.org/stories/Invisibles_plastics/" target="_blank" rel="noopener">microfibers </a>existed in 94 percent of the samples tested.
<h2>Patagonia Studies</h2>
In acknowledgment of their role in the early popularization of synthetic fleece, over the past several years Patagonia commissioned two scientific research studies to assess how many microfibers a single washing machine cycle releases, and compared their own products to off-brand fleece. 

<a href="https://pubs.acs.org/doi/abs/10.1021/acs.est.6b03045" target="_blank" rel="noopener">The results</a> found that one fleece garment can shed up to 250,000 microfibers; that both older and lower-quality clothing sheds more microfibers than newer and higher-quality clothing; and that top-load machines shed more than front-load machines.
<h2>Can the Spread of Fleece Microfibers Be Stopped?</h2>
Patagonia responded to their studies’ findings with plans to inform customers about microfibers and proper care for synthetic items, as well as the benefits of using washing machine filters. 

Patagonia is also helping fund a company called Tersus Solutions, which invented a waterless washing machine that cleans clothing with pressurized carbon dioxide. 

However, it’s unlikely that consumers would purchase these machines for the sole purpose of preventing fiber loss from their fleeces. 

Other recent studies suggest that apparel companies like Patagonia could mitigate the proliferation of microfibers with knitting techniques designed to reduce fiber loss, tighter yarns, and pre-washing and vacuuming textiles at manufacturing facilities. 

Additionally, beyond the apparel industry, wastewater treatment plants could install filtration systems.

There’s also precedent for legislation limiting the production of microplastics. The US banned microbeads, a type of microplastic used in toothpaste and cosmetics, with the passing of the Microbead-Free Waters Act in 2015. 

In 2018, California lawmakers struck down a bill that would require clothing with more than 50 percent microfiber-containing synthetic materials to have a label informing consumers to hand-wash the product.

Less than half a century since the advent of fleece, microfibers are everywhere—in oceans, marine life, and even our drinking water. 

Though it's probably impossible to reverse the damage that’s already been done, changes in the manufacturing of synthetic apparel, the way consumers wash synthetic apparel, and new laws could help prevent the problem from getting any worse.

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The Dirty Secret of Fleece: Microfibers and Plastic Pollution

Since outdoor clothing brand Patagonia introduced fleece in the early...

Huge,Hurricane,Between,Florida,And,Cuba.,Elements,Of,This,Image

Hurricanes and tsunamis are two types of powerful natural disasters that can destroy coastal communities overnight.&nbsp;These natural disasters may have similar effects, but the way they are created is very different. 



<h2 class="wp-block-heading" id="h-what-is-a-tsunami">What is a Tsunami?</h2>



Tsunamis are a series of ocean waves that are caused by large disturbances to ocean waters. Unlike normal waves, which are caused by wind running across the top of the ocean, tsunamis begin with a large movement of rock through earthquakes, volcanoes, or landslides.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_517577971-1024x649.jpg" alt="" class="wp-image-1897987"/><figcaption class="wp-element-caption">A diagram showing the different potential origins of tsunamis. </figcaption></figure>



Earthquakes cause tsunamis because they suddenly shift a large area of the seafloor. This disturbance displaces massive amounts of water and introduces energy into the ocean. The displacement and energy creates enormous waves called tsunamis.



Landslides into the ocean also cause tsunamis. Imagine the waves that form from dropping a ball into a pool. Now imagine how big those waves would be if the ball was the size of an entire cliff face falling into the ocean. The splash from such a falling cliff face can cause tsunami-sized waves.&nbsp;



Underwater volcanic explosions can also cause tsunamis by creating underwater landslides and by displacing large amounts of water.



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_1121215391-1024x878.jpg" alt="" class="wp-image-1897989"/><figcaption class="wp-element-caption">A diagram shows how a tsunami wave becomes larger the closer it gets to land. </figcaption></figure>



<h3 class="wp-block-heading" id="h-how-is-a-tsunami-different-from-a-regular-wave">How is a Tsunami Different From a Regular Wave?</h3>



Tsunami waves are unlike regular waves. They travel 500 miles per hour, which is as fast as an airplane! This means that a tsunami caused by an earthquake off the coast of South America can hit Japan within 24 hours. Tsunami waves appear as small waves in the open ocean. 



As tsunamis approach land, they grow in height. Most tsunamis are under 10 feet (3m) high. However, exceptional tsunami waves can be up to 500 feet high at landfall. This type of tsunami looks like a wall of water and is incredibly destructive to coastal areas. 



Tsunamis come as a series of waves. These waves usually peak within a few hours of the first wave that makes landfall. Smaller waves can continue for days. &nbsp;&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_712156006.jpg" alt="" class="wp-image-1897990"/><figcaption class="wp-element-caption">A hurricane heads towards Florida. </figcaption></figure>



<h2 class="wp-block-heading" id="h-what-is-a-hurricane">What is a Hurricane?</h2>



A hurricane is a massive, powerful storm that begins over the Atlantic ocean in the warm months between June and November. Hurricanes only form over a warm body of water because that warmth acts as fuel for the storm. When the winds of a tropical storm pass 74mph (119kph) they turn into hurricanes. 



The rotation of the Earth gives momentum to hurricanes, causing the iconic spiral pattern. Interestingly, these mega-storms spin counterclockwise in the northern hemisphere and clockwise in the summer hemisphere due to the spin of the Earth. Scientists break hurricanes into categories of 1-5, with category 5 having the fastest winds of over 157mph. 



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_1544007491-1024x985.jpg" alt="" class="wp-image-1897991"/><figcaption class="wp-element-caption">A diagram shows the formation of a hurricane. </figcaption></figure>



As with any storm, hurricanes create an area of low pressure underneath them. For strong hurricanes, this area has such low pressure that the ocean water bulges underneath the storm. 



The lesser pressure means that there is less weight of the atmosphere pushing down on the water, which allows the water to bulge skywards. When the hurricane carries this bulge of water towards land, it is called a storm surge. Hurricanes can carry storm surges <a href="https://www.earth.com/news/hurricanes-water/" target="_blank" rel="noreferrer noopener">far inland</a>, depending on the strength of the storm. 



Thunderstorms, heavy rain, destructive winds, and flooding accompany hurricanes.



<h2 class="wp-block-heading" id="h-where-do-these-natural-disasters-hit">Where do These Natural Disasters Hit?</h2>



Tsunamis can occur in any coastal area of the world. The most severe tsunamis usually hit land that borders the Indian Ocean and the North Pacific, around the Ring of Fire. Alaska, <a href="https://www.earth.com/news/japan-risk-tsunami/" target="_blank" rel="noreferrer noopener">Japan</a>, Hawaii, and India experience some of the worst and most frequent tsunamis in the world.&nbsp;



There are three words for the same type of storm that causes a hurricane. Cyclones, hurricanes, and typhoons are all the same thing, just in different areas. In the North Atlantic&nbsp;ocean or the Pacific ocean off of Mexico, the storm is called a hurricane. Areas surrounding the Gulf of Mexico, such as Florida and the Caribbean, often get hit by hurricanes. 



Typhoons are the same as hurricanes, but they form in the western Pacific&nbsp;ocean. Typhoons hit the Pacific side of Southeast Asia and Oceania. Tropical storms in the Indian Ocean are called cyclones. These storms wreak havoc on countries like India and Bangladesh.&nbsp;



Southern Asia and Indonesia are unfortunately in the path of both tropical cyclones and tsunamis.&nbsp;



<h2 class="wp-block-heading" id="h-is-a-tsunami-or-hurricane-more-destructive">Is a Tsunami or Hurricane More Destructive?</h2>



Tsunamis and hurricanes can both be incredibly destructive to coastal areas. The terrifying Boxing Day tsunami on December 26th, 2004 killed over 230,000 people in 14 countries around the Indian Ocean. The waves from this tsunami reached 100 feet high and ravaged communities through incredible flooding and force. 



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_1256683165.jpg" alt="" class="wp-image-1897992"/><figcaption class="wp-element-caption">Strong winds and flooding from a hurricane impact a coastal community.</figcaption></figure>



Severe tropical storms can be similarly destructive. The Bhola cyclone that hit Bangladesh in 1970 killed over half a million people. It flooded huge areas of the low-lying, heavily populated Ganges river delta.&nbsp;



While tsunamis like the <a href="https://knowledge.aidr.org.au/resources/tsunami-indian-ocean-boxing-day-tsunami-2004/" target="_blank" rel="noreferrer noopener">Boxing Day tsunami</a> are incredibly deadly, the majority of tsunamis do not end up killing that many people. With proper warning systems, people can usually find higher ground to avoid death by tsunami. From 1998-2017, tsunamis <a href="https://www.who.int/health-topics/tsunamis#tab=tab_1" target="_blank" rel="noreferrer noopener">killed about 250,000 people</a> around the world (most of which were in the Boxing Day tsunami). Hurricanes, cyclones, and typhoons are more deadly on average. In the 20th century, these storms killed about 2 million people worldwide. These tropical storms are not so easy to outrun. In addition to causing <a href="https://www.earth.com/news/hurricanes-water/" target="_blank" rel="noreferrer noopener">flooding by waves</a>, tropical storms cause inland flooding with heavy rain and further destruction with high winds. 



However, both tsunamis and tropical storms can impact millions of people at once. The most important aspect to the destructiveness of these natural disasters is where they hit. If a tsunami hits an ocean bluff that is 100 feet high with few people living on it, it will be orders of magnitude less destructive than smaller tsunami that hits a heavily populated, low-lying area. 



As humans continue to build in coastal areas, we increase our expposure to natural disasters such as hurricanes and tsunamis. Rising sea levels from climate change amplify storm surges, causing worse flooding. Climate change also fuels stronger and more frequent hurricanes. As we move into the future, adapting to these natural disasters will be increasingly difficult the warmer our planet becomes. 



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Tsunami vs. Hurricane: What's the Difference?

Hurricanes and tsunamis are two types of powerful natural disasters...

Deep-sea,Stingray

70% of the world's surface is the ocean - and much to the horror of humans through the millennia, scary sea monsters are actually a real thing. They prowl the vast waters of our globe and emerge with terrifying results in stories - and real life.&nbsp;



From the Atlantic to the Pacific oceans, from the North to the coast of New Zealand, there are fascinating sea creatures that strike fear into the hearts of the bravest explorers and threaten the most unsuspecting coastal tourist. At the same time, these scariest sea animals are wonderful, enchanting, <a href="https://www.earth.com/news/deep-sea-vents-are-favorable-to-the-formation-of-life/" target="_blank" rel="noreferrer noopener">living examples of evolution</a>, adaptive behaviors, and thrilling possibilities within nature.&nbsp;



Perhaps that's why they play such a massive role in our collective imaginations as well: the Kraken of Nordic sea lore, the loch ness monster of Scotland, the Lukwata sea monster of Uganda. The list of fables, legends, and sea shanties is as deep as the deep-sea waters where some monstrous animals swim. Science is just beginning to catch up and we can look to organizations like NOAA (National Oceanic and Atmospheric Administration) and MBARI (Monterey Bay Aquarium Research Institute) and others for emerging information on the truth behind the scary stories.&nbsp;



So let's dive in: today we'll look at the ecosystem of the ocean - the playground and habitat of an estimated one million animal species - and rip through some flash-points of the scariest swimming creatures among the masses. We'll also look at the ways in which the changing, warming oceans make even the most fearsome creatures vulnerable to disturbance and possible extinction. Scary stories abound!&nbsp;



<h2 id="h-an-ecosystem-of-monstrous-proportions">An Ecosystem Of Monstrous Proportions</h2>



When you think about it, the ocean itself is a bit of a monster - a living, breathing system of giant proportions.&nbsp;



For example, most life on earth is aquatic. Less than 5% of the oceans have been explored. The longest Mountain range is underwater. <a rel="noreferrer noopener" href="https://kealakai.byuh.edu/twenty-fun-facts-about-the-ocean" target="_blank">70% of the world's oxygen</a> - a fiendish amount - is produced by the ocean. The pressure on the seafloor will crush you. 90% of the Earth's volcanic activity happens in the ocean and the <a href="https://earth.google.com/web/@-18.57813014,147.57013641,-41.94434357a,0d,60y,201.23400896h,83.69613794t,0r/data=ClUaUxJNCiUweDZiZGYxNDQ2ODIyYzcxM2I6MHgxOTJhNTc0MTM2ODMzY2RhGXLEtTV9STLAITRUe8dfdmJAKhJHcmVhdCBCYXJyaWVyIFJlZWYYASABIjAKLEFGMVFpcE5ZdE5CTzd6bi01bGxXVzNEbGxTbGtxRHAxS0FTaGM4Q1JvZWR2EAU">great barrier reef</a> of Australia is so massive it can be seen from the moon.&nbsp;



The stats continue on in epic, sublime ways: the largest blue whale on record is as long as an 11-story building. The rounded sound ever recorded was of an iceberg falling into the ocean - and could be <a rel="noreferrer noopener" href="https://kealakai.byuh.edu/twenty-fun-facts-about-the-ocean" target="_blank">heard 3,000 miles away.</a> The ocean exists as a living fossil of itself, providing important clues and records of sea animals what has occurred on planet earth. It contains limitless secrets for us to slowly piece together, like a salty sea foam puzzle.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/shutterstock_1137771782.jpg" alt="" class="wp-image-1900841"/><figcaption><a href="https://www.shutterstock.com/g/posteriori">posteriori</a>/Shutterstock.com</figcaption></figure>



<h2 id="h-some-specific-scary-sea-monsters">Some Specific Scary Sea Monsters</h2>



There are plenty of secrets of the monstrous seven seas that we have yet to understand. But there are plenty of real-life sightings to send a shiver-of-a-jellyfish sting up your spine.&nbsp; The depths of the ocean are where mysticism meets horror movies - and the surface is by no means safe, either.&nbsp; Read on for a thoroughly-inconclusive list.&nbsp;



<h3 id="h-box-jellyfish">Box Jellyfish&nbsp;</h3>



Box Jelly is especially scary because to encounter a box tentacle is usually a death sentence for a human being. Named for their shape, they are considered the <a href="https://oceanservice.noaa.gov/facts/box-jellyfish.html" target="_blank" rel="noreferrer noopener">most venomous animal</a> in the ocean according to NOAA.&nbsp;



Their tentacles are loaded with poison darts known as nematocysts. People and animals that encounter these booby-trap-laden strings can become paralyzed, have heart failure, and die within minutes. There are 50 or so species of box jellyfish, and only a couple have the venom count to kill people. Those species are found in the Ind-Pacific region and Australia. Terrifyingly, they do not live in deep water but are a coastal species.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/shutterstock_68332459.jpg" alt="" class="wp-image-1900842"/><figcaption><a href="https://www.shutterstock.com/g/lienkie">Daleen Loest</a>/Shutterstock.com</figcaption></figure>



<h4 id="h-is-it-actually-dangerous">Is It Actually Dangerous?</h4>



Yes - box jellyfish live up to the hype. We often do not live up to their tentacles. Avoid these sea creatures at all costs.&nbsp;



<h3 id="h-frilled-shark">Frilled Shark</h3>



The frilled shark is what many scientists consider a "living fossil" with its strange lizard-like head, ruffled throat, <a rel="noreferrer noopener" href="http://www.elasmo-research.org/education/ecology/deepsea-frilled_shark.htm" target="_blank">long body, and tiny fins.</a> It definitely looks a lot like how a "sea serpent" of folklore is described. While it doesn't exactly add validity to stories like the Loch Ness monster or the Midgard serpent, it does have an "enchanting beast" quality to its appearance.&nbsp;



Frilled sharks rarely swim up to surface waters. Instead, they are a species of shark that moves through various life cycles in the area of the ocean known <a rel="noreferrer noopener" href="http://www.elasmo-research.org/education/ecology/deepsea-frilled_shark.htm" target="_blank">as the "twilight zone". </a>Want to take a look at another "living fossil" of the <a rel="noreferrer noopener" href="https://www.earth.com/earthpedia-articles/everything-youve-wanted-to-know-about-deep-sea-fishing/" target="_blank">deep sea</a> with an unnerving smile? Check out the <a rel="noreferrer noopener" href="https://www.jstor.org/stable/3877998" target="_blank">Goblin Shark.</a>&nbsp;



<h4 id="h-is-it-actually-dangerous-1">Is It Actually Dangerous?</h4>



No - these sea monsters just look scary. They are active predators but pose no threat to humans.&nbsp;&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/shutterstock_134776526.jpg" alt="" class="wp-image-1900858"/><figcaption><a href="https://www.shutterstock.com/g/demarfa">Natursports</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-fangtooth-fish">Fangtooth Fish</h3>



Fangtooths have a look that will haunt your dreams - and will continue to inspire the art-imitates-life-forms of various installations and horror films. It has <a href="https://www.earth.com/earthpedia-articles/5-strangest-deep-sea-creatures/" target="_blank" rel="noreferrer noopener">razor-sharp teeth of terrifying lengths</a> - perfect for catching prey such as fish and crustaceans.&nbsp;



They are deep-sea swimmers along with Anglerfish. Their habitat ranges in tropical and temperate seas <a rel="noreferrer noopener" href="https://www.montereybayaquarium.org/animals/animals-a-to-z/fangtooth" target="_blank">at 1,640 to 6,561 feet deep.</a>



<h4 id="h-is-it-actually-dangerous-2">Is It Actually Dangerous?</h4>



No - these fangtooths live so deep, they pose no threat to us - just the other animals that they feast and hunt for.&nbsp;



<h3 id="h-viperfish">Viperfish&nbsp;</h3>



Another fish with an appearance that can absolutely give you nightmares is the viperfish. It's a broad title for any species of marine fish in the genus Chauliodus. These species are characterized by needle-like teeth and hinged jaws that will remind you of an underbite.&nbsp;



These are also deep-sea swimmers. Similar to other species living in the dark depths of the ocean, they lure in their prey with <a rel="noreferrer noopener" href="https://academic.oup.com/sysbio/article-abstract/1/3/113/1696037" target="_blank">light-producing organs called photophores.</a>



<h4 id="h-is-it-actually-dangerous-3">Is It Actually Dangerous?</h4>



Nope - again, these fish swim so deep that they pose no risk to us.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/Giant_squid-1-1024x921.jpg" alt="" class="wp-image-1900860"/><figcaption>Specimen of giant squid nicknamed&nbsp;Wheke&nbsp;plastinated&nbsp;from 2005 and displayed on 26&nbsp;March 2008 in the&nbsp;Grande galerie de l'Évolution&nbsp;of the&nbsp;muséum national d'histoire naturelle&nbsp;in Paris. Photo via <a href="https://en.wikipedia.org/wiki/National_Museum_of_Natural_History,_France#/media/File:Giant_squid.jpg">Wikipedia.org</a>.</figcaption></figure>



<h3 id="h-giant-squid">Giant Squid</h3>



Indeed, the giant squid is much more than a fictionalized creature in the lake on the Hogwarts School Of Witchcraft And Wizardry grounds. The giant squid is a real-life animal and the second-largest mollusc we know of in Earth's history. It is an excellent example of deep-sea gigantism, <a rel="noreferrer noopener" href="https://daily.jstor.org/why-deep-sea-creatures-get-weirdly-giant/" target="_blank">a phenomenon and zoology term</a> that describes species of animals that are significantly larger than their shallow-water cousins.&nbsp;&nbsp;



Why is this? <a href="https://www.jstor.org/stable/3838549?mag=why-deep-sea-creatures-get-weirdly-giant&amp;seq=1#metadata_info_tab_contents" target="_blank" rel="noreferrer noopener">McLain et al.</a> propose that "limited resources [in deep water] select for larger body sizes that can better withstand periods of famine or ability to cover larger distances in search of scarce prey."&nbsp;



In 2019, a giant squid sighting was documented <a rel="noreferrer noopener" href="https://www.nytimes.com/2019/06/21/science/giant-squid-cephalopod-video.html" target="_blank">on video near the Gulf of Mexico</a>, reigniting the public's fear and fascination. In this instance, the squid was only a juvenile but was still an estimated 10 feet long.&nbsp;



<h4 id="h-is-it-actually-dangerous-4">Is It Actually Dangerous?</h4>



<a href="https://www.tepapa.govt.nz/discover-collections/read-watch-play/science/colossal-squid/difference-colossal-squid-giant-squid-octopus" target="_blank" rel="noreferrer noopener">Squid and octopus</a> (giant, or otherwise) are formidable fighters. While they do not typically attack humans, they are well equipped to defend themselves if they feel threatened.



<h3 id="h-vampire-squid">Vampire Squid</h3>



A name worthy of a horror movie in and of itself, the vampire squid is indeed a real-life thing - - a sea creature that is actually quite small with an intriguing appearance. It's scientific name&nbsp; is Vampyroteuthis infernalis. It lives in tropical and temperate waters in areas identified by "extreme deep-sea conditions". It is the only known survivor of the order Vampyromorphida and is a species that produces bioluminescence.&nbsp;



The arms of this squid will <a href="http://www.thecephalopodpage.org/vsfh.php" target="_blank" rel="noreferrer noopener">regenerate if bitten or ripped off.</a> Often, the discarded limbs then act as a diversion for the vampire squid to escape. It's a defense mechanism that is equal parts scary and amazing.&nbsp;



<h4 id="h-is-it-actually-dangerous-5">Is It Actually Dangerous?</h4>



According to NOAA, vampire squids are not even slightly dangerous to humans - they simply live too deep for us to encounter them.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/shutterstock_390021130.jpg" alt="" class="wp-image-1900862"/><figcaption><a href="https://www.shutterstock.com/g/Martin+P">Martin Prochazkacz</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-great-white-shark">Great White Shark&nbsp;</h3>



One of Finding Nemo's charming villains with a soft side, the Great white shark is no stranger to our psyches. Horror stories, films, and encounters abound.&nbsp;



These monsters are a species of large mackerel shark found in the coastal waters of all major oceans. It's only predator in the wild is, occasionally, the killer whale.&nbsp;



While scientists explain that humans are not the "<a href="https://web.archive.org/web/20090426174140/http://news.nationalgeographic.com/news/2004/01/0123_040123_tvgreatwhiteshark.html" target="_blank" rel="noreferrer noopener">preferred prey</a>" of the great white shark - it's just that these creatures are curious, and are willing to take a taste test. Not a comforting thought for surfers and swimmers, to say the least.&nbsp;



Similar to the drama around bears, lions, and tigers on land, the idea of a shark attack ends up being much bigger, culturally, than the actual risk. For example, there were <a href="https://www.floridamuseum.ufl.edu/shark-attacks/yearly-worldwide-summary/" target="_blank" rel="noreferrer noopener">8 reported shark attacks in 2021</a>. For some context, over 40% of the world's human population lives in coastal areas. These attacks are exceedingly rare.&nbsp;



<h4 id="h-is-it-actually-dangerous-6">Is It Actually Dangerous?</h4>



Even if these attacks are more rare than we might realize, there's no doubt about it. Great white sharks are dangerous animals.&nbsp;



<h2 id="h-protecting-our-sea-monsters">Protecting Our Sea Monsters&nbsp;</h2>



Of course, the scariest story of all the scariest sea monster stories are the monstrous implications of human impact on our oceans, coastlines, and fragile marine ecosystems.&nbsp;



In addition to warming water and unknown impacts on deep sea migration and global currents impacting weather, there are the immediate crises that our societies must address.&nbsp;



<a href="https://oceanservice.noaa.gov/hazards/beach-dangers/" target="_blank" rel="noreferrer noopener">Contaminated water</a> from oil rigs, untreated sewage, boats, pets, broken septic systems, and fertilizers accumulate in the ocean. People become outraged when their favorite swimming beach is closed due to dangerous contamination - and yet, the companies and public industry responsibility is rarely held accountable or reformed in a sustainable way.&nbsp;



The same goes for the terrifying amounts of plastic in our oceans, in the bodies of the animals that live there, and of course, <a href="https://oceanservice.noaa.gov/hazards/beach-dangers/" target="_blank" rel="noreferrer noopener">in our own systems.&nbsp;</a>



And of course, there is a lot of conversation about the fishing industry - much overdue - and the ways in which extractive and exploitative fishing methods ravage the populations of tasty fish, <a href="https://oceanservice.noaa.gov/facts/coral-overfishing.html" target="_blank" rel="noreferrer noopener">and demolish additional species</a> habitats and behaviors in the process.&nbsp;



Scary sea creatures are impacted by all of this of course - along with the more beloved marine-dependent creatures that whole throngs of people identify with - like sea turtles, dolphins, lobsters and other crustaceans, Giant Isopods, crocodiles, and oh so many species of birds. There is an endlessly nuanced web of life that depends on healthy oceans. All of it, ourselves included, depends on our ability to shift our own species' behavior. Either we do so or we are the true monsters.



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Scary Sea Monsters That Are Actually Real

70% of the world's surface is the ocean - and...

The,Marine,Iguana,Poses.,/,The,Marine,Iguana,Poses,On

There aren't all that many marine reptiles. Turtles, crocodiles, and sea snakes make up the bulk of the 100 species of marine reptiles. The marine iguana is the only lizard that is able to use both land and aquatic environments!



<h2 id="h-what-are-iguanas">What Are Iguanas?</h2>



Iguanas are a family of reptilian lizards (Iguanidae) native to South America, Central America, and some parts of the Caribbean islands. Iguanas are part of the Squamata order of reptiles (or reptilia in Latin), which includes all species of&nbsp;lizards, snakes, and worm lizards. All iguanas are fairly strict herbivores. They graze on various plants for sustenance. &nbsp;Iguanas, like many other reptiles, lay eggs. The incubation period for iguana eggs ranges from two to four months. A distinctive feature of iguanas is their dewlap, which is that funny flap of skin below their chin. Fun fact: cows, dogs, rabbits, and many other vertebrates have dewlaps!



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_681714934.jpg" alt="" class="wp-image-1898974"/><figcaption>The green iguana is a troublesome pest in southern areas of the U.S. <a href="https://www.shutterstock.com/g/AnaCrisMont">AnaCrisMont</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-do-iguanas-live-in-the-u-s">Do Iguanas Live in the U.S.?</h3>



Common species, such as the green iguana (scientific name&nbsp;Iguana iguana), or sometimes called American iguana, are invasive species in places like Texas, Hawaii, and Florida. Iguanas can thrive in a variety of climates, from the tropical rainforests of Puerto Rico to the deserts of the U.S.-Mexico borderlands. The desert iguana, for example, is a native to the brutal Sonoran desert of the southwestern U.S. and northwestern Mexico. The spiny-tailed iguana, in contrast, lives in the jungles of Mexico's Yucatan peninsula.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_1908998569.jpg" alt="" class="wp-image-1898975"/><figcaption>The dragon-like cyclura iguanas face many threats. <a href="https://www.shutterstock.com/g/Blue+Sky+imagery">Blue Sky imagery</a>/Shutterstock.com</figcaption></figure>



Iguanas are a semi-common pet for herpetology enthusiasts. While some types of iguanas can be raised in captivity, the illegal pet trade endangers some populations and species of iguanas. Other genera in the iguana family, such as the Cyclura iguanas of the West Indies, are among the most endangered species in the world.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_683241898.jpg" alt="" class="wp-image-1898976"/><figcaption>Lizards enjoying that island lifestyle. <a href="https://www.shutterstock.com/g/Marco+Mancini">Discover Marco</a>/Shutterstock.com</figcaption></figure>



<h2 id="h-marine-iguanas-only-live-on-the-galapagos">Marine Iguanas Only Live On the Galapagos</h2>



Marine iguanas, like much of the life on the Galapagos Islands, are an evolutionary anomaly. Scientists believe these lizards <a href="https://onlinelibrary.wiley.com/doi/abs/10.1046/j.1365-294X.1997.00209.x" target="_blank" rel="noreferrer noopener">floated on ocean debris</a> from mainland Ecuador to the Galapagos millions of years ago. In fact, the lizards may have arrived on the islands before any of the current islands existed! The Galapagos are a volcanic island chain. As the&nbsp;<a href="https://www.earth.com/earthpedia-articles/supercontinents-101-pannotia-gondwana-and-pangea/" target="_blank" rel="noreferrer noopener">tectonic plates</a>&nbsp;move over the volcanic hotspot, new islands are formed. The islands the lizards initially landed on have eroded into the sea.&nbsp;



<h2 id="h-marine-iguanas-live-like-this">Marine Iguanas Live Like This</h2>



Marine iguanas, like all other iguanas,&nbsp;<a href="https://www.earth.com/earthpedia-articles/what-do-marine-iguanas-eat/" target="_blank" rel="noreferrer noopener">live on an herbivorous diet</a>. Instead of eating land-based plants, these strange lizards eat underwater algae. Marine iguanas typically live to be about 12 years old, but some individuals have reached the ancient age of 60.



<h2 id="h-a-day-in-the-life-marine-iguanas-unique-adaptations">A Day in the Life: Marine Iguanas' Unique Adaptations</h2>



Because they have such an unusual lifestyle, marine iguanas have some unusual evolutionary adaptations compared to other lizards. Let's walk through a day in the life of a marine iguana and see how these adaptations help these creatures.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_693844036.jpg" alt="" class="wp-image-1898977"/><figcaption>A marine iguana swims through the water. <a href="https://www.shutterstock.com/g/Andy+Deitsch">Andy Deitsch</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-swimming-with-crocodile-like-tails">Swimming With Crocodile-Like Tails</h3>



You wake up on the rocky beach with an empty belly; you're a hungry iguana. All of your food is in the ocean, so you slink off to the waves for some breakfast.



Marine iguanas have special tails that help them swim. These tails are shaped like crocodile tails, which are long and muscular. They use these tails to swim in a snake-like pattern. Without these tails, these lizards would not be able to maneuver in the water. With the tails, however, these lizards are excellent swimmers that can access all sorts of underwater vegetation. These cold-blooded creatures' body temperature can drop by&nbsp;<a href="https://www.jstor.org/stable/1441131" target="_blank" rel="noreferrer noopener">more than 10C</a>&nbsp;during one foraging session in the cold Pacific Ocean. Incredibly, these lizards appear to behave normally when their body temperatures are as low as 77F and as high was 104F. That broad range of temperatures surely makes us humans look like weaklings in comparison. Hypothermia sets in when human body temperature sinks below a mere 95F and fever sets in above 100F.&nbsp;



The marine iguanas name may be slightly misleading. While these lizards are killer swimmers, they don't spend all that much time in the water. In fact, these lizards only&nbsp;<a href="http://special%20salt-excretion%20glands%20the%20white%20scales%20around%20their%20face%20might%20appear%20as%20simply%20scales%20with%20different%20color%20pigment.%20instead%2C%20these%20scales%20are%20white%20because%20of%20an%20interesting%20trait.%20marine%20iguanas%20live%20in%20very%20salty%20environs.%20they%20ingest%20substantial%20amounts%20of%20salt%20as%20they%20forage%20for%20algae%20underwater.%20in%20high%20concentrations%2C%20salts%20can%20be%20toxic%20and%20dehydrating.%20in%20response%20to%20high%20salt%20levels%2C%20these%20water-loving%20lizards%20evolved%20a%20special%20gland%20near%20their%20nose%20that%20excretes%20excess%20salts%20in%20their%20bodies.%20these%20salt%20glands%20are%20incredibly%20efficient%20at%20expelling%20salt%20from%20the%20marine%20iguana%27s%20bodies.%20the%20iguanas%20then%20spread%20these%20salts%20around%20their%20nose%20through%20daily%20activities.%20instead%20of%20white%20pigmentation%2C%20the%20white%20is%20simply%20salt%20deposits%21%20%20a%20marine%20iguana%20swims%20through%20the%20water./" target="_blank" rel="noreferrer noopener">spend about 5% of their time</a>, or one hour a day, actually submerged and swimming in the water. &nbsp;



In order to avoid dropping their body temperature too much, these lizards also forage on algae in the&nbsp;<a href="http://the%20marine%20iguanas%20name%20may%20be%20slightly%20misleading.%20while%20these%20lizards%20are%20killer%20swimmers%2C%20they%20don%27t%20spend%20all%20that%20much%20time%20in%20the%20water.%20in%20fact%2C%20these%20iguanas%20only%20spend%20about%205%25%20of%20their%20time%2C%20or%20one%20hour%20a%20day%2C%20actually%20submerged%20and%20swimming%20in%20the%20water./" target="_blank" rel="noreferrer noopener">inter-tidal zone.</a>&nbsp;When the tide goes out, it exposes algae on rocks that were previously underwater. Inter-tidal feeding doesn't suck as much heat out of the lizards' bodies.



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_797312221.jpg" alt="" class="wp-image-1898978"/><figcaption>The talons on this iguana help it grip onto rocks as it feeds on algae. <a href="https://www.shutterstock.com/g/Bryan+Chu">Bryan Chu</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-talons">Talons</h3>



Once you find a nice pasture of algae, you use your talons to secure yourself to the rock as you graze. You spend a while using your mouth to pick algae off of rocks. This tasty algae is your main source of food.&nbsp;



These special lizards also evolved long, sharp, strong talons to help them grip on to rocks while they forage. Without these claws, waves could easily sweep the lizards away from their tasty algae patches while they feed. With these claws, the lizards can cling on to rocks through turbulent conditions.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_1901979757.jpg" alt="" class="wp-image-1898979"/><figcaption>Young iguanas sun themselves to warm up from the cold ocean. <a href="https://www.shutterstock.com/g/Andreas+Stahre">Andreas Stahre</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-iguanas-enjoy-beach-bummin">Iguanas Enjoy Beach Bummin'&nbsp;</h3>



You've just spent an hour foraging in the frigid Pacific ocean. With a belly fully of algae, it is time to warm up!&nbsp;



All lizards are cold-blooded animals, which mean they need external heat to regulate their body temperatures. Marine iguanas are very dark colored because that color helps them absorb the most amount of heat from the sunshine. By basking in the sunlight, these lizards raise their body temperatures after being in the cold water.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_2010115664.jpg" alt="" class="wp-image-1898980"/><figcaption>A marine iguana sneezes salts out of its salt glands. <a href="https://www.shutterstock.com/g/martinmark">Maridav</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-special-salt-excretion-glands">Special Salt-Excretion Glands</h3>



While eating all that algae in the ocean, you also consumed a lot of ocean water. After your body efficiently concentrates the salt in your body, you spend a while sneezing that salt out of the&nbsp;<a href="https://www.jstor.org/stable/1447726" target="_blank" rel="noreferrer noopener">special salt glands</a>&nbsp;in your nose. After sneezing out your salt and warming up, you realize it is low tide so you forage on in the inter-tidal zone. Then, more basking! That's more or less the life of a marine iguana.&nbsp;



The white scales around a marine iguana's face might appear as simply scales with different color pigment. Instead, these scales are white because of an interesting trait. Marine iguanas live in very salty environs. They ingest substantial amounts of salt as they forage for algae underwater. In high concentrations, salts can be toxic and dehydrating. In response to high salt levels, these water-loving lizards evolved a special gland near their nose that excretes excess salts in their bodies. These salt glands are incredibly efficient at expelling salt from these lizards' bodies. The lizard then spread these salts around their nose through daily activities. Instead of white pigmentation, the white is simply salt deposits!



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_204443467.jpg" alt="" class="wp-image-1898981"/><figcaption>It's time to sleep after a hard day's work! <a href="https://www.shutterstock.com/g/estivillml">Marisa Estivill</a>/Shutterstock.com</figcaption></figure>



<h2 id="h-marine-iguanas-on-different-galapagos-islands-are-distinct">Marine Iguanas on Different Galapagos Islands Are Distinct</h2>



While these is only one species of marine iguana, there is almost a unique subspecies on every Galapagos Island. Much like the evolution of Darwin's Finches, these lizards have evolved to exploit their hyper-specific environments.&nbsp;



Interestingly, this lizard appears in many sizes. In an area with a high quality algae pasture, these adult&nbsp;male iguanas can grow to be&nbsp;<a href="https://esajournals.onlinelibrary.wiley.com/doi/abs/10.1890/0012-9658(1997)078[2204:ELTBSI]2.0.CO;2" target="_blank" rel="noreferrer noopener">ten times the weight</a>&nbsp;of adult&nbsp;male iguanas in areas with low quality pasture! Additionally, these heavier lizards can be two times longer than their less-nourished brethren.&nbsp;



Its not always good to be bigger, however. During the weather pattern of El Niño, the warmer ocean waters decrease the lizards's algae pastures. As these algae pastures become less rich, the&nbsp;<a href="https://socobilldurham.sites.stanford.edu/sites/g/files/sbiybj10241/f/soco_08_-_dame_boyle_allison.pdf" target="_blank" rel="noreferrer noopener">larger lizards tend to suffer first and hardest</a>&nbsp;while the smaller lizards tend to do okay. A larger marine iguana needs to eat more algae to keep its body functioning. When there is less algae overall that is much harder to do!



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_520808293.jpg" alt="" class="wp-image-1898982"/><figcaption>Isn't that a nice smile? <a href="https://www.shutterstock.com/g/Donya+Nedomam">Don Mammoser</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-threats-to-marine-iguanas">Threats to Marine Iguanas</h3>



Even though they are in a protected island chain in the middle of the ocean, these marine lizards face various threats. As ocean temperatures warm with climate change, the algae pastures will likely decrease in quality. This means that every year could be akin to a El Niño famine year for these special marine lizards. Non-native animals on the Galapagos are also a threat to these lizards. These lizards did not evolve with land predators, so they don't know how to react to non-native animals like&nbsp;<a href="https://www.sciencedirect.com/science/article/abs/pii/S0018506X07001961" target="_blank" rel="noreferrer noopener">cats and dogs</a>. Cats and dogs can easily kill the unsuspecting lizards. protect their eggs from non-native animals like rats. Tourism is another threat to these lizards. Iguanas show&nbsp;<a href="https://www.sciencedirect.com/science/article/abs/pii/S0018506X10002114" target="_blank" rel="noreferrer noopener">measurable amounts of stress</a>&nbsp;when tourists approach them. The indirect impacts from&nbsp;<a href="https://link.springer.com/chapter/10.1007/978-3-319-02769-2_12" target="_blank" rel="noreferrer noopener">fishing tourism and pollution</a>&nbsp;also make life harder for these lizards. For these reasons, the marine iguana is listed as a threatened species.&nbsp;



If you are ever lucky enough to visit the Galapagos Islands, remember to keep your distance from these unique creatures while you appreciate their unusual lifestyle.  



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There Are Only 100 Marine Reptiles: The Iguana

There aren't all that many marine reptiles. Turtles, crocodiles, and...

Waves,Of,Water,Of,The,River,And,The,Sea,Meet

Earth’s waters are constantly moving. They change form in the water cycle. They flow from the tiniest streams to the biggest rivers. Even on the stillest days in the ocean, the water is never quite static. In fact, ocean water movement can be summed up in three genres: currents, tides, and waves. Though just a thin layer on the earth’s crust, the forces both on and outside our planet treat our oceans like putty. Celestial bodies like the sun and moon push and pull the oceans as the earth hurtles through space. Similarly, the Earth’s own gravity and rotation impact oceanic movement.&nbsp;



But waves, tides, and currents are each distinct from one another depending on their temporal and physical scale along with their behavior. Here we’ve outlined the important distinctions between waves, tides, and currents.



<h2 id="h-currents">Currents</h2>



Currents are predictable and directional movements of water that persist for longer periods of time. Occurring at all ocean depths from the intertidal to the benthic zones, currents impact the earth’s climate by carrying pockets of heat around the globe.&nbsp;



<h3 id="h-creating-currents">Creating Currents</h3>



A combination of wind, sun, gravity, and the Earth’s rotation influences our planet’s currents. And all four factors are quite interconnected. Radiation from the sun creates wind. Prevailing winds create peaks and valleys in the ocean water, while gravity pulls water toward the valleys. Finally, the Earth’s rotation is the soup spoon stirring the pot to create direction.&nbsp;



<figure class="wp-block-image alignnone size-full wp-image-1893436"><img src="https://www.earth.com/wp-content/uploads/2021/07/shutterstock_137936432.jpg" alt="ocean currents around the world" class="wp-image-1893436"/><figcaption>Ocean currents move water around the globe in a consistent and directional flow. <a href="https://www.shutterstock.com/g/designua">Designua</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-sun-wind">Sun &amp; Wind</h3>



Similar to their impact on climate, the wind and sun control the ocean currents. Prevailing winds are air currents that stay consistent in a specific place or during a specific season. They push water around the globe in predictable patterns. But where do the winds come from? That’s where we look a bit further from the earth’s atmosphere… to the sun!



The sun’s radiation is strongest at the equator and dissipates toward the poles. Consequently (and perhaps obviously), the air at the equator heats up and moves north and south while the air at the poles cools down and moves toward the equator. Fronts of hot and cold air pockets collide to create pressure differentials. Combined with other factors, the resulting wind currents cause peaks and valleys in the ocean’s surface. Though they are subtle to an ocean traveler, the peaks are called “<a href="http://www.tsgc.utexas.edu/topex/activities/topex_basics/topex08.html" target="_blank" rel="noopener">sea surface hills</a>,” and can be detected by satellites.&nbsp;



<h4 id="h-gravity-rotation">Gravity &amp; Rotation</h4>



The earth’s forces play a significant role in directing the ocean’s currents. The peaks and valleys created by the sun and wind are immediately at the whim of gravity. Gravity pulls the water down from the hills toward the valleys. But the water never travels in a straight line. Because of the earth’s rotation, gravity pulls the water into the valleys in a curving trajectory. These currents can be further explained by the Coriolis Effect.



<figure class="wp-block-image alignnone size-large wp-image-1893437"><img src="https://www.earth.com/wp-content/uploads/2021/07/shutterstock_1841520682-1024x811.jpg" alt="coriolis effect" class="wp-image-1893437"/><figcaption>The Coriolis Effect. <a href="https://www.shutterstock.com/g/Fouad+A.+Saad">Fouad A. Saad</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-the-coriolis-effect">The Coriolis Effect</h3>



You’ve probably heard of the <a href="https://earth.usc.edu/~stott/Catalina/Oceans.html" target="_blank" rel="noopener">Coriolis Effect</a> either in the context of climate or plane travel. The Coriolis Effect explains the influence of the Earth’s rotation on objects in a fluid environment (i.e. not on solid ground). Because the Earth is a sphere, a point on the equator (the largest circumference) will travel at a higher velocity than a point closer to one of the poles. This gets really interesting when we think of how this impacts currents.&nbsp;



<ul><li style="font-weight: 400;">North or South Movement: When water moves in a northern or southern direction, it continues moving at its starting velocity. Since the earth rotates counterclockwise (from west to east), the flow of water moving away from the equator will be pulled to the right with the direction of rotation since it started at a higher velocity. On the other hand, water moving away from the poles starts is moving slower than the rotation closer to the equator. Therefore those currents will be pulled in a clockwise direction against the rotation of the Earth.&nbsp;</li><li style="font-weight: 400;">East or West Movement: Currents that flow toward the east or west are affected by the earth’s rotation in a whole different way. If a current travels to the east with the rotation, it speeds up and is pulled toward the Equator. On the other hand, a current traveling west in the opposite direction of the earth’s rotation will slow down and be pulled toward one of the Earth’s poles.&nbsp;</li></ul>



Water depth does impact these trends. As the ocean deepens, the Coriolis Effect pulls water at slightly different angles.



<h3 id="h-currents-ecology">Currents &amp; Ecology</h3>



Just as currents move different <a href="https://www.earth.com/news/marine-heatwaves-will-intensify-in-the-strongest-ocean-currents/" target="_blank" rel="noopener">temperatures of water</a> around the world, they provide free transportation for ocean life. Turtles and whales use currents to help speed up their annual migrations across the open ocean. Additionally, many species find new homes and increase their genetic diversity by traveling with currents. And not just animals use them! Currents carry mats of seaweed, ocean algae, and even debris like logs and trash across the globe.



<h2 id="h-waves">Waves</h2>



While ocean currents take water thousands of miles around the globe, waves move water at a much smaller scale. Though waves impact a microcosm of the earth, they have a powerful influence on local ecosystems and coastlines. Ocean waves form due to the force of the wind rushing across the surface of the water. They are distinct from currents and tides because of their shape, longevity, and direction.



The wind speed, duration of gust, and the area of water that the wind blows over (aka the fetch) impact the wave height. The famous surfing waves of Hawaii, Tahiti, and California result from a long buildup over huge expanses of open water. Waves can also be tiny. They are considered mere ripples when they are less than one foot tall. To <a href="https://www.earth.com/earthpedia-articles/basic-ocean-terms/" target="_blank" rel="noopener">measure a wave</a>, scientists use the same vocabulary that sound waves are measured in, including trough and crest, amplitude, and frequency.



<h3 id="h-waves-ecology">Waves &amp; Ecology</h3>



Though small in scale compared to currents and tides, waves exert a powerful influence on coastal areas due to their repetitive nature. Everything from shallow water waves to tidal waves shapes coastlines by adding and taking away substrate. Through this give and take, waves create shoreline habitats.



<h2 id="h-tides">Tides</h2>



Tides are distinct changes in sea level across great expanses due to the gravitational pull of the sun and moon. Essentially, large waves that rush from one side of the ocean to the other, tides create a huge impact on the earth’s shorelines.



<h3 id="h-stages-of-tides">Stages of Tides</h3>



A flood tide describes the time when the rising water covers the intertidal zone to reach its maximum water height at high tide. Subsequently, the water lowers to reveal the intertidal zone, called the ebb tide. Finally, the low tide means the water reaches its lowest level and begins the process again.&nbsp;



<h3 id="h-what-causes-the-tides">What Causes the Tides?</h3>



Tides are caused by the <a href="https://www.whoi.edu/cms/files/lecture01_21351.pdf" target="_blank" rel="noopener">gravitational forces</a> of the moon and sun on the earth’s oceans. Due to the moon’s orbit, it changes location throughout the day. Depending on which side of the earth it’s on, it pulls the world’s oceans in that direction.



Though tidal patterns are primarily impacted by the moon’s position, gravity from the sun can also play a role. When the sun and moon line up with the earth at a new moon and full moon, they create a celestial event called a syzygy. In these moments, the sun amplifies the gravitation pull of the moon. Consequently, the <a href="https://www.earth.com/news/supermoon-causes-high-tides-in-the-uk/" target="_blank" rel="noopener">tides intensify</a> with highs and lows reaching monthly extremes. These events are known as spring tides.&nbsp;



On the other hand, a half-moon forms a 90° angle with the earth and sun, completely losing any amplification from the sun. Half-moons produce neap tides which are the monthly minimums of the tidal range.



<h3 id="h-types-of-tides">Types of Tides</h3>



Tides typically appear in one of three categories based on their frequency and tide height: diurnal tides, semidiurnal tides, and mixed tides. Diurnal tides cycle once per day with a single high tide and single low tide. Semidiurnal tides have two high tides and two low tides with their tide heights being approximately equal. Lastly, mixed tides usually have two highs and two lows, but one high tide and one low tide will be more extreme than the others.



<h3 id="h-tides-ecology">Tides &amp; Ecology</h3>



Operating on a slower timescale than waves, though with similar predictability, tides impose an enormous influence on the world’s ecology. Tidal pools provide sanctuary for delicate marine invertebrates and a reliable food source for the shorebirds and marine mammals that peruse tidal zones. Some creatures, like sea turtles, rely on the outgoing tides to help with juvenile dispersal.



<figure class="wp-block-image alignnone size-full wp-image-1893439"><img src="https://www.earth.com/wp-content/uploads/2021/07/shutterstock_179293964.jpg" alt="tide pools" class="wp-image-1893439"/><figcaption>Tide pools provide sanctuaries for marine life. <a href="https://www.shutterstock.com/g/Ethan+Daniels">Ethan Daniels</a>/Shutterstock.com</figcaption></figure>



&nbsp; &nbsp; Marine and coastal wildlife aren’t the only creatures that rely on the tides for habitat and food. Humans have learned to harness <a href="https://www.earth.com/news/sea-energy-power-future/" target="_blank" rel="noopener">tidal power</a> for our own benefit. Similar to harnessing the wind, using turbines to capture tidal energy provides a sustainable energy source for coastal communities worldwide.



<h2 id="h-waves-tides-and-currents-continuous-movement">Waves, Tides, and Currents: Continuous Movement</h2>



The complexities of the oceans don’t stop here. The saying that we know more about the surface of the moon than we do about the oceans continues to prove itself true as marine biologists continue to make new discoveries. While we still have plenty to learn about the ocean in general, having a greater appreciation for the distinct ways that the oceans move is a good start.



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Wave, Tides, Currents: An Important Distinction

Earth’s waters are constantly moving. They change form in the...

Layers,Of,Sedimentary,Sandstone,Rock.

Just as biologists need to distinguish between different kinds of plants and animals, geologists depend on being able to classify different types of rocks. It turns out that the best way to classify rocks is based on the process in which they were formed. There are three main processes that result in the three overarching categories of rocks. These categories, which we will explore in detail, are igneous, sedimentary, and metamorphic rocks.



<h2 id="h-minerals-are-the-building-blocks-for-different-types-of-rocks">Minerals Are The Building Blocks for Different Types of Rocks</h2>



Minerals are the building blocks of rocks, but they are not rocks in and of themselves. Rocks are aggregates of different kinds of minerals. Granite is a classic example of this. The distinct granules of color in granite are different kinds of minerals. Together, those mineral crystals make the resulting granite rock.



Each mineral has a unique chemical composition that influences the characteristics of the resulting mineral. For example, quartz is silica dioxide. Quartz is always hard and either transparent or translucent. Other minerals have their own characteristics.



Some examples of other common minerals include feldspar, mica, and carbonate.



<figure class="wp-block-image alignnone size-full wp-image-1893050"><img src="https://www.earth.com/wp-content/uploads/2021/07/shutterstock_790494358.jpg" alt="" class="wp-image-1893050"/><figcaption>Rubies are a special type of aluminum oxide mineral. The extra chromium in the aluminum oxide gives rubies their color. <a href="https://www.shutterstock.com/g/moussa81">Victor Moussa</a>/Shutterstock.com</figcaption></figure>



<h2 id="h-igneous-types-of-rocks">Igneous Types of Rocks</h2>



The super-hot center of our&nbsp;Earth&nbsp;is liquid magma, or&nbsp;molten rock. When this&nbsp;magma cools&nbsp;as a result of getting closer to the&nbsp;Earth's surface, it forms&nbsp;igneous rocks. Just as water turns to ice in the freezer, liquid magma turns into solid rocks when it comes into contact with cooler temperatures. The inside of the&nbsp;Earth&nbsp;is about 2500 degrees Fahrenheit, so anywhere near the&nbsp;Earth's crust&nbsp;is very cold in comparison.



There are two main categories of&nbsp;igneous rocks; intrusive and&nbsp;extrusive.



<figure class="wp-block-image alignnone size-full wp-image-1893051"><img src="https://www.earth.com/wp-content/uploads/2021/07/shutterstock_1958468266.jpg" alt="" class="wp-image-1893051"/><figcaption>Brand new extrusive igneous rock forms as this lava cools on Iceland. <a href="https://www.shutterstock.com/g/ronen+barany">ImageBank4u</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-extrusive-igneous-rocks">Extrusive Igneous Rocks</h3>



It is a bit easier to imagine the formation of&nbsp;extrusive&nbsp;igneous rocks. These rocks form when lava (which is magma when it reaches the surface of the&nbsp;Earth) cools into rocks. <a href="https://www.earth.com/news/volcanic-rock-earths-ancient/" target="_blank" rel="noopener">Volcanoes</a> form&nbsp;extrusive&nbsp;igneous rocks&nbsp;when they erupt.



The lava cools from a liquid to a solid incredibly quickly during this process. This quick cooling results in smaller mineral grains within the rock. In general, if an igneous rock has mineral crystals that are smaller than 1mm, it is an extrusive igneous rock.



This rapid cooling can result in unusual rocks. Volcanic glass has no mineral crystals because the lava cooled so fast none were able to form. Pumice is a rock that floats because air was trapped in the lava and wasn't able to escape before the lava cooled. These air pockets are bubbles in the rock that allow it to float. Other examples of extrusive igneous rocks include pumice, basalt, andesite, rhyolite, and obsidian.



<figure class="wp-block-image alignnone size-full wp-image-1893052"><img src="https://www.earth.com/wp-content/uploads/2021/07/shutterstock_528577123.jpg" alt="" class="wp-image-1893052"/><figcaption>People love to use granite, an intrusive igneous rock, as a material for countertops. Notice the various sizes of mineral grains in these granite types. <a href="https://www.shutterstock.com/g/Design+Studio+D">StudioDin</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-intrusive-igneous-rocks">Intrusive Igneous Rocks</h3>



Intrusive igneous rocks, on the other hand, form from the cooling of magma below the Earth's surface. This crystallization happens in hotter environments. Since intrusive rocks form more slowly, their mineral crystals are larger than 1mm. Examples of intrusive igneous rocks include diorite, gabbro, and granite.



<figure class="wp-block-image alignnone size-full wp-image-1893044"><img src="https://www.earth.com/wp-content/uploads/2021/06/shutterstock_244510456.jpg" alt="the wave metamorphic" class="wp-image-1893044"/><figcaption>The Wave in Arizona is one of the most stunning displays of sedimentary rock. <a href="https://www.shutterstock.com/g/Oscity">Oscity</a>/Shutterstock.com</figcaption></figure>



<h2 id="h-sedimentary-types-of-rocks">Sedimentary Types of Rocks</h2>



While lava and magma are the basis of igneous rocks, sediments are the building blocks of sedimentary rocks. Sediments are small bits of rocks caused by the erosion, or breaking down, of other rocks. Water and wind cause this erosion, which is sometimes called weathering.



Sediments can be incredibly small or as large as boulders. The size of the sediment granules determines the resulting sedimentary rock.&nbsp;<a href="https://www.tulane.edu/~sanelson/eens1110/sedrx.htm" target="_blank" rel="noopener noreferrer">Sediment&nbsp;types</a> in order from smallest to largest are clay, silt, sand, pebble, cobble, and boulder. These 'boulders' are anything over 25cm, or about one foot. Clay, on the other hand, is any sediment smaller than 1/256th of a millimeter.



After eroding from their parent rocks, these sediments are either pressed together or glued together to form sedimentary rocks. This process is lithification.



Plate tectonics and even the Earth's climate determine sedimentary rock formation. Geologists can <a href="https://www.earth.com/news/ancient-ocean-tides-desert-rock/" target="_blank" rel="noopener">see ancient tides</a>&nbsp;and&nbsp;<a href="https://www.earth.com/news/western-interior-seaway/" target="_blank" rel="noopener">sea levels</a>&nbsp;in&nbsp;sedimentary rocks.



<figure class="wp-block-image alignnone size-full wp-image-1893045"><img src="https://www.earth.com/wp-content/uploads/2021/06/shutterstock_652472320.jpg" alt="grand canyon sedimentary" class="wp-image-1893045"/><figcaption>The Grand Canyon is a sedimentary rock lover's dream. <a href="https://www.shutterstock.com/g/amandamohler">Amanda Mohler</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-clastic-sedimentary-rocks">Clastic&nbsp;Sedimentary Rocks</h3>



Clastic sedimentary rocks form from compacted (pressed together) or cemented (glued together) sediments. Sediments compact when layers and layers of sediment get deposited over the same area. The weight of the upper layers presses down on the weight of the lower layers, which compacts the lower layers into rocks.



Cementation happens when water flows through compacted sedimentary rocks. Water is almost never pure because it usually carries minerals as it flows. As this minerals-laden water flows through compacted sediment, some of the minerals in the water settle into the pores in the rock. This process is called cementation. This is also how fossils form, which is why sedimentary rocks are the only rocks with fossils in them.



If a&nbsp;clastic&nbsp;sedimentary rock&nbsp;is formed from clay-sized particles, it is called shale. Sand-sized particles make sandstone, silt-sized result in siltstone, and larger particles make&nbsp;conglomerate&nbsp;rocks.



<figure class="wp-block-image alignnone size-full wp-image-1893046"><img src="https://www.earth.com/wp-content/uploads/2021/06/shutterstock_1176092938.jpg" alt="" class="wp-image-1893046"/><figcaption>Coal is an economically important bioclastic rock. <a href="https://www.shutterstock.com/g/Coast+Productions">CMPMLD</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-bioclastic-sedimentary-rocks">Bioclastic&nbsp;Sedimentary Rocks</h3>



These are the only rocks made from life itself! Organic sedimentary rocks form in the same way as clastic rocks, but the parent 'rock' isn't a rock at all. Instead, the parent material is a type of life. Examples include crushed up seashells and layers upon layers of dying plants or algae. Seashells result in limestone and the dying plants create coal.



<figure class="wp-block-image alignnone size-full wp-image-1893047"><img src="https://www.earth.com/wp-content/uploads/2021/06/shutterstock_1940914003.jpg" alt="" class="wp-image-1893047"/><figcaption>Halite forms as an evaporate sedimentary rock in a dry lakebed. <a href="https://www.shutterstock.com/g/StephenBridger">Stephen Bridger</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-evaporate-and-precipitate-sedimentary-rocks">Evaporate and Precipitate&nbsp;Sedimentary Rocks</h3>



Precipitate and evaporate types of sedimentary rocks are a little more difficult to understand. Evaporate rocks occur when mineral-laden water consistently evaporates in the same place over and over again. When the water evaporates it leaves behind any minerals it was carrying. Over a long period of time, these minerals build up to create layers of sediment, which then compress into rocks.



An example of evaporate rocks is halite. As salty water evaporates, it leaves behind salt (NaCl), which over geologic time becomes halite.



Precipitate rocks occur when minerals fall out of a body of water. Water can only carry a certain amount of minerals. If the water has any more minerals than it can carry, these minerals fall to the bottom of the body of water. Again, over time this precipitation of minerals creates layers that compact each other. Gypsum forms through precipitation.



<figure class="wp-block-image alignnone size-full wp-image-1893048"><img src="https://www.earth.com/wp-content/uploads/2021/06/shutterstock_756694396.jpg" alt="" class="wp-image-1893048"/><figcaption>Ribbons running throughout a rock are indicative of metamorphic rocks. <a href="https://www.shutterstock.com/g/lespalenik">LesPalenik</a>/Shutterstock.com</figcaption></figure>



<h2 id="h-metamorphic-types-of-rock">Metamorphic Types of Rock</h2>



The final category of rocks is metamorphic rocks. Like sedimentary rocks, metamorphic rocks form from parent rocks. When rocks are heated or squished hard enough through pressure, they change into metamorphic rocks. The two methods of metamorphic rock formation are contact and regional metamorphism.



<h3 id="h-contact-metamorphism">Contact&nbsp;Metamorphism</h3>



Have you ever gotten burned by touching something really hot? Did your skin blister and look a little bit different where it was burned? This is basically how contact&nbsp;metamorphism&nbsp;works. When lava or magma comes in contact with existing solid rock, the liquid magma superheats the rock that it is touching. This extreme oven created by the magma bakes the&nbsp;existing rock&nbsp;into something different. That&nbsp;existing rock&nbsp;metamorphizes into a contact&nbsp;metamorphic rock. Contact&nbsp;metamorphism&nbsp;requires lots of heat.



<h3 id="h-regional-metamorphism">Regional&nbsp;Metamorphism</h3>



Regional&nbsp;metamorphism&nbsp;requires pressure instead of heat. There is an incredible amount of pressure where two&nbsp;<a href="https://www.earth.com/earthpedia-articles/supercontinents-101-pannotia-gondwana-and-pangea/" target="_blank" rel="noopener">tectonic&nbsp;plates</a> converge. This pressure squeezes the&nbsp;existing rocks&nbsp;so hard that they metamorphize into regional&nbsp;metamorphic rocks.



Sometimes&nbsp;metamorphic rocks&nbsp;form by a combination of both regional and contact processes.



<h3 id="h-the-metamorphic-rock-grade">The&nbsp;Metamorphic Rock&nbsp;Grade</h3>



Geologists put metamorphic rocks on a scale from low grade to high grade. The lower the grade of rocks means the metamorphosis happened with less temperature and pressure. The higher-grade rocks experience higher temperatures or pressure. The types of rocks that form (in order from low to high grade) are called slate, phyllite, schist, and gneiss. Typically, with any additional pressure or heat, gneiss will melt and turn back into magma.



<h3 id="h-the-rock-cycle">The&nbsp;Rock Cycle</h3>



The rocks on&nbsp;Earth&nbsp;are constantly changing, but the amount of minerals and magma on&nbsp;Earth&nbsp;is not. This is because rocks go through the&nbsp;rock cycle. This cycle isn't the same for every rock, but it always starts with rocks being born as&nbsp;igneous rocks. They are then weathered into&nbsp;sedimentary rocks&nbsp;or smushed into&nbsp;metamorphic rocks. At some point, they will melt back into the&nbsp;Earth's mantle and become&nbsp;igneous rocks&nbsp;again one day.



Quartzite is a great example of the rock cycle. When quartz erodes from an igneous rock it sometimes makes a sedimentary rock of pure quartz sediment. This pure quartz sandstone can then undergo metamorphic processes, which turn it into quartzite. Therefore, any quartzite has, at one point, been magma, igneous, sedimentary, and metamorphic.



<h2 id="h-these-types-of-rocks-are-just-the-beginning">These Types of Rocks are Just the Beginning</h2>



Geologists&nbsp;have named hundreds of&nbsp;types of rocks. Knowing the basic methods of formation for igneous, metamorphic, and&nbsp;sedimentary rocks&nbsp;is only the surface of an entire field of study.



The types of rocks in an area can give us clues into what Earth has looked like throughout time. For example, metamorphic rocks can act as the writing in a book about our Earth's tectonic past. By knowing the depths, temperatures, and ages of different types of metamorphic rocks form at, <a href="https://www.earth.com/news/earths-plate-tectonics-evolution/" target="_blank" rel="noopener">scientists can piece together</a> the development of Earth's plate tectonics. Geologists can learn all sorts of surprising insights by examining these rocks!



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You've been rocking on the boat all day and haven't had even the faintest nibble. Suddenly, the line jerks and you run over to it to begin an hours-long battle with the mystery fish. Imagine the thrill of finally pulling a 1000 pound marlin out of the depths of the open ocean during your deep-sea fishing charter. It's a thrill that some fisherpeople get addicted to, a feeling they live for.
Our deep oceans contain the biggest fish in the world. Fishers will travel the world over for the chance to reel in a honkin' tuna or a shiny Dorado. Deep-sea fishing is a considerable recreation and travel industry that supports fishing guide businesses around the world.


[caption id="attachment_1892427" align="alignnone" width="1920"]<img class="wp-image-1892427 size-full" src="https://www.earth.com/wp-content/uploads/2021/06/sea-3652697_1920.jpg" alt="open ocean" width="1920" height="1280" /> Ain't much to look at when you're deep-sea fishing. Photo by <a href="https://pixabay.com/users/dimhou-5987327/" target="_blank" rel="noopener">Dim Hou</a> via <a href="https://pixabay.com/photos/sea-water-ocean-quiet-horizon-3652697/" target="_blank" rel="noopener">Pixabay</a>.[/caption]
<h2>What is Deep-Sea Fishing?</h2>
Most people call any type of recreational fishing done below 100 feet in ocean waters deep-sea fishing.  While commercial fishing boats often fish at these depths, this article won't cover that kind of deep-sea fishing.
Any sort of freshwater or saltwater bay fishing isn't considered deep water fishing. Since the deep seas are, by their nature, far from land, deep-sea fishing is always done on a boat. Sometimes boats can get to deep-sea depths relatively close to shore. Other times this sort of fishing is done dozens, or even hundreds, of miles from the nearest land.
Some fisherpeople also call this type of fishing sport fishing or trophy fishing.


[caption id="attachment_1892430" align="alignnone" width="1280"]<img class="wp-image-1892430 size-full" src="https://www.earth.com/wp-content/uploads/2021/06/hanging-3045269_1280.jpg" alt="deep-sea fishing lures" width="1280" height="835" /> Various kinds of deep-sea fishing lures. Photo by <a href="https://pixabay.com/users/paulbr75-2938186/" target="_blank" rel="noopener">Paul Brennan</a> via <a href="https://pixabay.com/photos/hanging-hook-lures-fishing-3045269/" target="_blank" rel="noopener">Pixabay</a>.[/caption]
<h2>Different Types of Deep-Sea Fishing</h2>
Most fishers hire a guiding company for their deep-sea fishing excursions. These fishing charters vary depending on the location, guide company, and species of fish. One thing is certain; deep-sea fishing isn't for those without their sea legs. The open ocean has big, rolling waves, which constantly rock even the nicest boats. With only water on the horizon, even strong-stomached anglers can get nauseous. You can opt for either a deep-sea fishing charter with a group or as a private charter.
Guides will usually let their customers try various kinds of fishing methods during a deep-sea fishing excursion. These methods can include trolling, chumming, popping, and jigging. Trolling is where anglers dangle their lines behind a quickly moving boat, sometimes with live bait. Chumming includes throwing bait onto the water to lure deep-sea fishes up to the surface. Jigging is a type of lure fishing where the lure is attached to a lead weight that makes it dance in a particular way deep beneath the surface. Fishers usually set these jigs at various depths with the boat slowly drifting along. Popping is a more unusual way to deep-sea fish. It involves using larger lures called 'poppers' that slap the water to make sounds that entice nearby fish.

<h3>Half-Day Trips</h3>
The cheapest option for sport fishing trips is usually a half-day tour. These shorter tours typically don't go too far from the land because it takes a long time to venture way out into the ocean.

<h3>Full-Day Trips</h3>
Full-day fishing trips are a common type of trophy fishing. These charter boats leave the shore early in the morning and sometimes return after sunset. Full-day trips give anglers a better chance of trying different methods of deep-sea fishing.

<h3>Night Fishing Adventures</h3>
Some kinds of fish only bite at night. To catch these fish some guides lead night-time deep-sea fishing tours.

<h3>Multi-Day Excursions</h3>
These deep-sea fishing trips are the creme de la creme. While they are the most expensive, they also offer the widest variety of opportunities. Fishers can expect to fish during different times of day with multiple methods. This variety gives anglers the best chance to catch their dream fishes.


[caption id="attachment_1892431" align="alignnone" width="1280"]<img class="wp-image-1892431 size-full" src="https://www.earth.com/wp-content/uploads/2021/06/boat-5429345_1280.jpg" alt="deep-sea fishing" width="1280" height="857" /> Dorado, or mahi-mahi, is an exciting deep-sea fish species to catch. Photo by <a href="https://pixabay.com/users/larsen9236-47917/" target="_blank" rel="noopener">Lisa Larsen</a> via <a href="https://pixabay.com/photos/boat-fishing-fishing-boat-5429345/" target="_blank" rel="noopener">Pixabay</a>.[/caption]
<h2>What Kinds of Fish do Sport Fisherpeople Catch?</h2>
Most of the desired deep-sea fish live in the pelagic zone of the ocean. The pelagic zone is all of the ocean that isn't close to some sort of boundary. These boundaries include the seafloor, the ocean surface, and any coast. Deep-sea fishers usually aren't going for <a href="https://www.earth.com/earthpedia-articles/seven-surprising-secrets-of-the-deepest-sea-creatures/" target="_blank" rel="noopener">those awfully strange</a>, truly deep-ocean fish that live near the seafloor. The pelagic ecosystem is based on photosynthetic plankton. These plankton live near the upper reaches of the pelagic zone because they need sunlight to live. Pelagic fishes will <a href="https://www.vox.com/unexplainable/22348461/ocean-twilight-zone-mysteries-unexplainable-podcast" target="_blank" rel="noopener noreferrer">migrate to different depths</a> or locations based on the availability of plankton.
All coasts of the U.S. have deep-sea fishing opportunities. The East coast <a href="https://www.frontiersin.org/files/Articles/491041/fmars-07-00012-HTML/image_m/fmars-07-00012-g005.jpg" target="_blank" rel="noopener noreferrer">represents about 40%</a> of recreational marine fishing. The Gulf of Mexico and Hawaii account for <a href="https://www.frontiersin.org/files/Articles/491041/fmars-07-00012-HTML/image_m/fmars-07-00012-g005.jpg" target="_blank" rel="noopener noreferrer">20% each</a>. Alaska and the West coast account for <a href="https://www.frontiersin.org/files/Articles/491041/fmars-07-00012-HTML/image_m/fmars-07-00012-g005.jpg" target="_blank" rel="noopener noreferrer">about 10% each</a>. Abroad, coastal countries around the world offer unique deep-sea charters and experiences.

<h3>West Coast</h3>
Off the California, Oregon, and Washington coast, people like to fish for yellowtail, sturgeon, albacore tuna, rockfish, barracuda, white sea bass, and lingcod. The ocean around California's Channel Islands is a uniquely beautiful place to fish with abundant deep-sea fisheries.

<h3>East Coast</h3>
Off the East coast of the U.S. people catch bluefin and yellowfin tuna, cod, striped bass, and <a href="https://www.earth.com/news/volcanic-eruption-fishing-industry/" target="_blank" rel="noopener">mackerel</a>. People can even leave for these trips from mega-cities like New York and Boston.

<h3>Gulf of Mexico</h3>
The Gulf of Mexico is a major deep-sea fishing destination. People can access the Gulf of Mexico from Florida, Texas, the eastern coast of Mexico, and the Caribbean islands. This gulf is a particularly biodiverse body of water, making it an interesting place to sport fish. Fishers can catch Dorado, shark, king mackerel, red snapper, and Spanish mackerel.

<h3>Alaska</h3>
Alaska is world-renowned for its fishing. This massive state has plenty of open ocean to choose from. Deep-sea fishers can expect to fish for massive halibut and salmon, as well as crab.

<h3>Hawaii</h3>
Who wouldn't want to fish the tropical waters of Hawaii? As the only islands for hundreds of miles around, Hawaii is an excellent jumping-off point to quickly access the true open ocean. Fishers can fish for awesome species in Hawaii like the Yellowfin ahi tuna, giant blue marlin, dorado, sailfish, swordfish, and wahoo.


[caption id="attachment_1892429" align="alignnone" width="1920"]<img class="wp-image-1892429 size-full" src="https://www.earth.com/wp-content/uploads/2021/06/charter-4682523_1920.jpg" alt="deep-sea fishing rods" width="1920" height="1281" /> Fishing rods wait for bites from deep-sea fish. Photo by <a href="https://pixabay.com/users/jasongillman-1088827/" target="_blank" rel="noopener">Jason Gillman</a> via <a href="https://pixabay.com/photos/charter-fishing-water-marine-4682523/" target="_blank" rel="noopener">Pixabay</a>.[/caption]
<h2>Does Deep-Sea Fishing Harm Fish Populations?</h2>
In raw numbers, deep-sea fishing doesn't account for a whole lot of the global fish take. <a href="https://www.frontiersin.org/articles/10.3389/fmars.2020.00012/full" target="_blank" rel="noopener noreferrer">Less than 1%</a> (by mass) of marine fish killed annually are by recreational fishers. Industrial fishing fleets take the vast bulk of the world's catch, with subsistence artisanal fishers taking varying degrees depending on the fishery. <a href="http://www.seaaroundus.org/data/#/eez/44?chart=catch-chart&amp;dimension=sector&amp;measure=tonnage&amp;limit=10" target="_blank" rel="noopener noreferrer">The Bahamas</a> is an extreme case where 30% of fish taken out of the ocean is for recreation.
However, even though recreational fishing doesn't take a huge amount of fish out of the ocean, some scientists are concerned with the species of fish and the particular individuals that recreational fishers target.

<h3>Small Numbers Can Be Deceiving</h3>
Even though deep-sea fishers don't catch that many fish, the particular species and individuals they target can affect fish populations. Trophy fishers often aim to catch the big fish species that reproduce slowly. <a href="https://www.biologicaldiversity.org/species/fish/Atlantic_bluefin_tuna/natural_history.html#:~:text=LIFE%20CYCLE%3A%20Atlantic%20bluefin%20tuna,octopus%2C%20crabs%2C%20and%20sponges." target="_blank" rel="noopener noreferrer">Tuna</a> often live 40 years. Most other deep-sea fishes sought by recreational fishers live decades. Fish that live a long time typically take more years to reach their reproductive age. This means that if the adults from a population of these fish are reduced by overfishing, it can take a long time for their population to rebound.
Moreover, sport fishers target the largest individuals of these slowly reproducing species. By their nature, these large fishes are <a href="https://www.sciencedirect.com/science/article/abs/pii/S0308597X14001754?via%3Dihub" target="_blank" rel="noopener noreferrer">often the best reproducers</a> in the population. Some scientists are concerned that targeting the healthiest individuals of a population puts significant pressure on the population. Sports fishers are increasingly turning to catch-and-release methods instead of killing fish. While this method is preferable from the fish's standpoint, it can <a href="https://www.earth.com/news/catch-release-fishing-damages/" target="_blank" rel="noopener">still have lasting impacts</a> on the fish.
In particular, the trophy fishing of <a href="http://www.seaaroundus.org/sea-around-us-collaborator-says-shark-fishing-should-be-considered-ocean-vandalism/#more-18610" target="_blank" rel="noopener noreferrer">threatened species of sharks</a> is alarming.
Lastly, outside of the U.S., <a href="https://www.frontiersin.org/articles/10.3389/fmars.2020.00012/full" target="_blank" rel="noopener noreferrer">scientists don't have much data</a> on what species of fish and how many fish recreational fishers take out of the oceans. Their estimates vary from 0.5 million tons per year to 10 million tons per year! Without this data, it is difficult to say the extent to which recreational fishing impacts fish populations.

<h2>Get Fishing!</h2>
With a fish species, a destination, and a budget in mind, you can figure out the fishing trip that is right for you. Maybe it's near your home, or perhaps it is a getaway to some tropical coastline half the world away. Best of luck on your angling adventures!
Featured image by <a href="https://pixabay.com/users/scottslm-10594535/" target="_blank" rel="noopener">Scott</a> via <a href="https://pixabay.com/photos/deep-sea-fishing-boat-fishermen-boat-5847660/" target="_blank" rel="noopener">Pixabay</a>.
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When one thinks of an insect, they usually don’t picture a six-legged animal diving and swimming through water. Yet, the giant water bug has certainly made a name for itself doing so. The huge insect is an aquatic killing machine, as it swims through the water hunting small prey like fish, snails, and other insects. It goes by many names, including toe-biters, electric light bugs, and fish killers. Their many names and odd appearance leads to some confusion about what the critters actually are. Water bugs are often mistaken for <a href="https://www.earth.com/news/cockroaches-survive-anything/" target="_blank" rel="noopener noreferrer">cockroaches</a> and other types of insects, so let’s clear up what exactly a water bug is, how to recognize one, and why they’re so cool!



<figure class="wp-block-image"><img src="https://www.earth.com/wp-content/uploads/2020/12/water-strider-691039_1920-1024x683.jpg" alt="water bug" class="wp-image-1886869"/><figcaption><a href="https://pixabay.com/users/a_different_perspective-2135817/">A_Different_Perspective</a> / Pixabay</figcaption></figure>



<h2 id="h-is-a-water-bug-an-insect-what-kind">Is a Water Bug an Insect? What Kind?</h2>



Remember that insects are animals with a hard outer shell called an exoskeleton, six legs, and three body segments. Water bugs fit the insect bill in every way, so yes, they’re insects! Let’s go a little bit deeper, though. What kind of insect is a water bug?



Insects are in their own class of animals called Insecta, which contains many different orders. When we talk about types of insects, we usually refer to the taxonomic rank of order without even realizing it. Some of the most common insect orders are beetles (order Coleoptera), butterflies and moths (Lepidoptera), and flies (Diptera). Water bugs are in the <a href="https://www.discoverlife.org/mp/20q?search=Hemiptera" target="_blank" rel="noopener noreferrer">order Hemiptera</a>. These are called the “true bugs”, a funny name considering how colloquial the word “bug” is.



Water bugs, along with <a href="https://www.earth.com/earthpedia-articles/what-is-a-stink-bug-and-why-do-they-stink/" target="_blank" rel="noopener noreferrer">stink bugs</a>, aphids, and cicadas, are all in the order Hemiptera. The order gets its name from having half (Hemi-) wings (ptera), because their forewings are only half membraneous, with the other half being hardened into a protective shield. Giant water bugs are in their own family called Belostomatidae.



<figure class="wp-block-image"><img src="https://www.earth.com/wp-content/uploads/2020/12/water-bug-1292227_1920-1024x575.jpg" alt="water bug" class="wp-image-1886870"/><figcaption><a href="https://pixabay.com/users/brett_hondow-49958/">Brett_Hondow</a> / Pixabay</figcaption></figure>



<h2 id="h-what-does-a-water-bug-look-like">What Does a Water Bug Look Like?</h2>



Giant water bugs are quite easy to recognize. First of all, they’re huge. They are usually at least two centimeters long (1 inch) but can be much, much larger. The largest species can reach lengths of up to 12 centimeters (4.5 inches), easily the length of a human hand! Aside from being really, really ridiculously big, giant water bugs can be recognized by a big “V” shaped pattern on their back.



<h2 id="h-where-do-water-bugs-live">Where Do Water Bugs Live?</h2>



Water bugs can be found all over the world. One of the more familiar species is Lethocerus americanus which is common in Southern Canada and the United States.



Giant water bugs live in aquatic and semi-aquatic environments. You can find them in freshwater ecosystems of all kinds, including ponds, <a href="https://www.earth.com/earthpedia-articles/salt-marsh/" target="_blank" rel="noopener noreferrer">marshes</a>, the banks of rivers and streams, and more. They typically like to hang out right underneath the surface of the water where they hide amongst vegetation or loose rock in order to escape predation when they aren’t hunting.



<figure class="wp-block-image"><img src="https://www.earth.com/wp-content/uploads/2020/12/wasserlaufer-5372086-1024x632.jpg" alt="water strider" class="wp-image-1886871"/><figcaption><a href="https://pixabay.com/users/siebeckdotcom-13589689/">siebeckdotcom</a> / Pixabay</figcaption></figure>



<h2 id="h-water-bug-behavior">Water Bug Behavior</h2>



Water bugs are famous mainly because of their hunting abilities. They have specialized limbs that allow them to be swim and hunt in the water with ease. For example, their hind legs are basically giant paddles. They are large and flat, and water bugs use these appendages to propel themselves through the water. They also have huge <a href="https://www.amentsoc.org/insects/glossary/terms/raptorial" target="_blank" rel="noopener noreferrer">raptorial forelegs</a> that snag and hold onto their prey, much like a praying mantis. These front appendages are what make water bugs such excellent hunters, as they are capable of catching prey much larger than themselves.



Once a water bug is holding its meal, it inserts a long, piercing mouthpart into its victim. First, saliva with digestive enzymes is injected into the prey. Then, the water bug sucks out the nutritious juices with its straw-like mouth. It's a rather gruesome end for the prey, but an effective method of eating for the water bug.



Despite their aquatic abilities, giant water bugs can’t actually <a href="https://www.earth.com/earthpedia-articles/how-do-amphibians-breathe/" target="_blank" rel="noopener noreferrer">breathe underwater</a>. Instead, they take up air at the surface like a snorkel and hold their breath as they dive. They can also create an air bubble underneath their wings, which they slowly use up while they’re underwater. It’s important to note that, unlike most animals, insects breathe through tiny holes in their abdomen. Other arthropods like spiders are able to do this as well, making them some of the first-ever scuba divers in the natural world!



Giant water bugs are also good parents, which is an unusual trait among insects. The male water bug cares for the eggs, often carrying them on his back before they hatch.



<figure class="wp-block-image"><img src="https://www.earth.com/wp-content/uploads/2020/12/water-2808949_1920-1024x576.jpg" alt="water striders" class="wp-image-1886873"/><figcaption><a href="https://pixabay.com/users/ddzphoto-5605533/">ddzphoto</a> / Pixabay</figcaption></figure>



<h2 id="h-should-i-be-afraid-of-water-bugs">Should I Be Afraid of Water Bugs?</h2>



The short answer is: No! Water bugs are vital parts of a healthy ecosystem and are mostly harmless to humans. However, they are known to bite humans, and this behavior is what gives them the name "toe-biters". Unfortunately, their bite can be quite painful. Luckily, it’s not all that common to be bitten by these bugs, and they only bite to defend themselves if they are handled or messed with. They prefer to escape the situation first, using a bite only as a last resort.



<h2 id="h-in-conclusion">In Conclusion</h2>



Giant water bugs are nothing to be afraid of unless you are a small insect or fish living underwater. If you’re a human, they are fascinating and charismatic insects that deserve more recognition. The large insects have a super interesting natural history and are a vital part of aquatic ecosystems. Now you know what they are, where to find them, and how they live!



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Everyone lives in a watershed and everyone's drinking water comes from a watershed, so it is important to know a little something about this exciting concept. &nbsp;



<h2 id="h-what-is-a-watershed">What is a Watershed?</h2>



A watershed is an area of land where all water that falls on that land drains to a single point. A watershed is also a drainage basin, where all water flows downhill towards a river, lake, or other body of water. The land that drains to a watershed is called the catchment area. High ridges divide watersheds since water that falls on one side of the ridge&nbsp;<a rel="noreferrer noopener" href="https://www.earth.com/earthpedia-articles/explaining-watersheds-with-9-examples/" target="_blank">drains to a different place</a>&nbsp;than water that falls on the other side of the ridge.&nbsp;







For example, all the land that drains water towards the Mississippi River is in the Mississippi River watershed. This watershed is the largest in North America. Can you believe that 31 states have land that drains towards the Mississippi!



While the Mississippi is the largest watershed, it is made up of many other sub-watersheds. The Arkansas River watershed is a smaller part of the larger Mississippi watershed. The Arkansas drains parts of Colorado, Kansas, New Mexico, Nebraska, Texas, Oklahoma, and Arkansas. Other major rivers, like the Ohio, Missouri, and Platte, all have their own watersheds within the larger watershed of the Mississippi. Diving even smaller, each creek and stream that flows into the Arkansas or Ohio rivers is its own smaller watershed.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/shutterstock_1964845897.jpg" alt="" class="wp-image-1902382"/><figcaption>Various illustrations that visually demonstrate drainage basins. <a href="https://www.shutterstock.com/g/Amadeu+Blasco">Amadeu Blasco</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-what-s-your-watershed">What's Your Watershed?</h3>



Can you figure out the watershed you live in? Start by locating the largest watershed and work all the way down to the smallest one. For example, if you lived in downtown Denver, Colorado, you would be in the massive Mississippi watershed, the big Platte River watershed, the moderate South Platte River watershed, and the small Cherry Creek watershed.&nbsp;



Bonus: can you figure out what watershed your tap water comes from?



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/shutterstock_1675839565-1024x653.jpg" alt="" class="wp-image-1902383"/><figcaption>A map of the major watersheds in the continental U.S. <a href="https://www.shutterstock.com/g/Rainer+Lesniewski">Rainer Lesniewski</a>/Shutterstock.com</figcaption></figure>



<h2 id="h-western-states-could-ve-been-defined-by-watersheds">Western States Could've Been Defined by Watersheds</h2>



John Wesley Powell, the first person to lead a boat trip down the entire Grand Canyon, was a scholar of the American West in the late 1800s. He wanted western states' boundaries to be the boundaries between watersheds. He thought that this arrangement would result in better water management in a&nbsp;<a rel="noreferrer noopener" href="https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?West" target="_blank">generally arid landscape</a>. Unfortunately for the watersheds, Powell's idea was not adopted. The northern border between Idaho and Montana follows a watershed boundary, but that's it! While the borders between California and Arizona are the Colorado River, that is not a boundary between two watersheds. Rather, that border just splits one watershed up.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/powellsmap-800x1024.jpeg" alt="western watershed map" class="wp-image-1900830"/><figcaption>John Wesley Powell's map of western watersheds. Each color blob shows what Powell would've liked to be its own state. Photo via <a href="https://commons.wikimedia.org/wiki/File:Map_of_Water_Sheds_of_Arid_Region_of_United_States_by_John_Wesley_Powell.jpg" target="_blank" rel="noreferrer noopener">Wikimedia</a>. </figcaption></figure>



Dividing arid watersheds between populous states has created immense difficulties. The Colorado River now faces huge water problems between the seven states that compose its watershed. In short, each state has overclaimed how much water it can draw from the river. When added up, the total amount of water allowed to be drawn between the seven states is about twice the annual discharge of the entire river. Utah, Colorado, Arizona, California, New Mexico, Nevada, and Wyoming now must make tough choices about how to divide up a resource that is much smaller than any of them planned for. Had politicians followed Powell's guidance, perhaps the management of water resources like the Colorado would make more sense. &nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/shutterstock_199194950.jpg" alt="" class="wp-image-1902385"/><figcaption>The Little Colorado River, true to its name, has very little water for how much land it drains. <a href="https://www.shutterstock.com/g/antonfoltin">LHBLLC</a>/Shutterstock.com</figcaption></figure>



<h2 id="h-what-affects-how-much-water-a-watershed-produces">What Affects How Much Water a Watershed Produces?</h2>



Many factors influence the volume of water that exits a watershed. Some very small watersheds produce copious amounts of water. The Elwah river on the Olympic Peninsula in Washington state discharges an&nbsp;<a rel="noreferrer noopener" href="http://www.clallam.net/environment/assets/applets/W18_2.4-ElwhaRiver.pdf" target="_blank">average of 1500</a>&nbsp;cubic feet of water per second. A cubic foot is about the same size as a basketball. The Elwah's watershed is&nbsp;<a rel="noreferrer noopener" href="http://www.clallam.net/environment/assets/applets/W18_2.4-ElwhaRiver.pdf" target="_blank">just 320 square miles</a>, or about the area of New York City. In contrast, the Little Colorado River watershed, which drains northeastern Arizona, has a flow of just 432 cubic feet per second even though it drains over 25,000 square miles of land! That means the Elwah watershed produces almost 300 times more water per acre than the Little Colorado. Why is the Elwah so much more productive than the Little Colorado?



<h3 id="h-precipitation-and-watershed-area-are-major-factors">Precipitation and Watershed Area are Major Factors</h3>



One obvious factor that impacts this difference is a drastic difference in precipitation. The Little Colorado drains arid, desert lands, while the Elwah drains lush rainforests. Land area is another basic factor in watershed productivity. A watershed with a larger area and the same annual precipitation will discharge more water than one with a smaller area.&nbsp;



&nbsp;However, precipitation and the area of the watershed are not the only factors that impact the productivity of a watershed.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/shutterstock_1089481091.jpg" alt="" class="wp-image-1902386"/><figcaption>A diagram that illustrates how water infiltrates into a groundwater aquifer. <a href="https://www.shutterstock.com/g/stihii">stihii</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-infiltration-evaporation-and-transpiration">Infiltration, Evaporation, and Transpiration</h3>



Infiltration is the ability of water to sink into soil and aquifers rather than running off into rivers. Soil, vegetation, and rock composition all affect the infiltration capacity of the land. More vegetation, for example, will slow water down as it moves across the landscape. This slower-moving water is more able to seep into the ground. If the geology allows, this water can eventually seep into underground aquifers instead of running out to the sea. The easier it is for water to infiltrate the soil, the less water makes it to a river.&nbsp;



Evaporation is when water changes from a liquid to a gas. If it is hot outside, water is more likely to evaporate into the air. When rain evaporates on the land, it doesn't run into rivers.&nbsp;



Transpiration happens when plants use water as they photosynthesize. When plants use water, they subtract the water they use from the discharge of the river of the watershed they are in (with some cool exceptions, like how the&nbsp;<a href="https://climate.nasa.gov/news/2608/new-study-shows-the-amazon-makes-its-own-rainy-season/" target="_blank" rel="noreferrer noopener">Amazon creates its own rain</a>).&nbsp;



<h2 id="h-water-use-by-humans">Water Use by Humans</h2>



Human uses of water change how much water flows through a watershed. In water-rich areas, the water use by humans is minimal compared to the water nature provides. However, in drier regions, rivers are usually used heavily. The Colorado river is utilized so much that it fails to reach the ocean. Humans take every drop out of the Colorado until there is no river left. Most of the human water use is for animal agriculture, crop agriculture, and industrial applications. A small amount of human water use is done by individuals. In California, a very populous state, urban areas use&nbsp;<a rel="noreferrer noopener" href="https://www.ppic.org/publication/water-use-in-california/" target="_blank">only 20% of human water use in the state</a>.&nbsp;



Another major human alteration to watersheds is dams. Nearly every river has a dam on it, and most rivers have multiple dams on them. There are&nbsp;<a rel="noreferrer noopener" href="https://infrastructurereportcard.org/cat-item/dams/#:~:text=As%20of%202019%2C%20there%20are,once%2Drural%20dams%20and%20reservoirs." target="_blank">almost 100,000 dams</a>&nbsp;in the U.S. alone! Dams regulate the flow of rivers, typically to be more predictable than the flow would be otherwise. The reservoirs created by dams change the character of a watershed immensely.



Humans have fundamentally altered some watersheds, such as the&nbsp;<a rel="noreferrer noopener" href="https://www.inyowater.org/documents/reports/owens-valley-water-history-chronology/" target="_blank">Owens River</a>&nbsp;in California. Historically, the Owens river drained into an inland lake on the eastern side of the Sierra Nevada. In the early 1900s, Los Angeles built an aqueduct to transport the Owens river to satisfy Los Angeles' growing water needs.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/shutterstock_1231977907.jpg" alt="" class="wp-image-1902387"/><figcaption><a href="https://www.shutterstock.com/g/MichaelVi">Michael Vi</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-urban-areas-change-wateresheds">Urban Areas Change Wateresheds</h3>



Urban areas drastically change watersheds, also. Humans replace soil with square miles of hard surfaces, like concrete and asphalt. When it rains on these surfaces, the water that would've soaked into the ground instead runs across parking lots, streets, sidewalks, and basketball courts towards storm drains, sewers, or river channels. These storm drains, along with stormwater runoff, carry urban pollution to creeks, rivers, and the ocean. Cities are trying to reduce the problems associated with impervious surfaces, such as concrete, by creating rain swales, making more parks, and educating the public about storm drains.&nbsp;



<h3 id="h-watershed-and-pollution">Watershed and Pollution</h3>



Since watersheds concentrate water to a single point, watersheds also&nbsp;<a href="https://www.earth.com/news/protecting-lake-erie-from-agricultural-runoff/" target="_blank" rel="noreferrer noopener">concentrate any pollution</a>&nbsp;that water carries to that single point. Often, fertilizers, pesticides, and sediment from agricultural fields runoff into rivers. This runoff causes all sorts of&nbsp;<a href="https://www.earth.com/earthpedia-articles/why-is-the-nitrogen-cycle-so-important/" target="_blank" rel="noreferrer noopener">environmental issues</a>. Government agencies monitor water quality and use that quality as an indicator of watershed health.&nbsp;



<h2 id="h-read-more-about-water">Read More About Water!</h2>



Water is the building block of all life. If deserves your attention. If you're interested in watersheds, there's no lack of material. There are so many interesting books, <a href="https://www.earth.com/earthpedia-articles/explaining-watersheds-with-9-examples/" target="_blank" rel="noreferrer noopener">articles</a>, videos, and podcasts about watersheds and how humans use water. Learning about your own watershed it one of the best ways to become connected to the place you live. 



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What is a Watershed? Am I In One?

Everyone lives in a watershed and everyone's drinking water comes...

Scientists are transforming chocolate into a functional food by infusing it with probiotics and prebiotics, aiming to create a treat that satisfies cravings while supporting gut health. 



The challenge lies in maintaining chocolate's beloved texture and flavor while adding health benefits.



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Probiotics - beneficial microbes that balance gut bacteria and aid digestion - are typically fragile and can be destroyed by stomach acid or processing. 



Prebiotics act as food for these microbes, helping them thrive. Together, they form "synbiotics," a powerful health combination.



Researchers Smriti Gaur and Shubhi Singh from India's Jaypee Institute of Information Technology took an innovative approach, using natural prebiotics like corn and honey instead of complex processing methods. 



They created five chocolate varieties: a control and four synbiotic versions containing different combinations of prebiotics, probiotics (Lactobacillus strains), and flavor enhancers (cinnamon or orange).



Laboratory simulations of human digestion showed the probiotics remained viable for over five hours, suggesting they could survive long enough to benefit gut health.



Taste tests were positive, with researchers particularly enjoying the orange-flavored variety, describing it as having "vibrant citrus notes" complementing the "rich cocoa" with a "luxurious" texture.



This research represents just the beginning. With further refinement of strains, textures, and flavors, chocolate could evolve beyond mere indulgence to become a functional food that nourishes while it delights.



The study is published in the journal <a href="https://pubs.acs.org/doi/10.1021/acsfoodscitech.4c00741" target="_blank" rel="noreferrer noopener">ACS Food Science &amp; Technology</a>.

Is chocolate the next nutritional powerhouse?

Scientists are transforming chocolate into a functional food by infusing...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Nushagak Bay, a large estuary in southwest Alaska. Nushagak runs mainly north to south and exits in Bristol Bay, a large body of water in the Bering Sea.



"The bay is primarily fed by the Nushagak River, which begins in the Alaska Range and flows southwest approximately 450 km. The bay is also fed by several additional rivers including the Wood, Igushik, Snake and Weary rivers," says ESA.



"The dark colors of the Nushagak River are most likely due to tannins or lignins (chemical substances found in plants). Tannins and lignins from roots, leaves, seeds, bark and soil can leach into the water and give it a brown or even black colour. The sediments then flow southwards where it is mixed with the bluer waters of the bay."



Video/ Image Credit: ESA



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Nushagak Bay in southwest Alaska

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> (ACS) reveals that proteins on flu viruses are actually flexible, tilting and waving in a “breath-like” motion. According to the experts, these proteins could be used to better defend against the flu.



"The main antigenic targets of influenza virus are two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). Whereas the structural and dynamical properties of both glycoproteins have been studied previously, the understanding of their plasticity in the whole-virion context is fragmented," wrote the researchers.



To investigate, the team conducted detailed simulations of the influenza A H1N1 virion, or the swine flu. The experts concluded that the visualizations show many new vulnerable states of flu viruses, which could improve future vaccines and antiviral drugs.



Video/ Image Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Flu viruses are more flexible than expected

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Lake Trasimeno, which is located west of Perugia in central Italy. It is the fourth largest lake in the country. While Trasimeno’s water level varies, it has a maximum depth of approximately six meters.&nbsp;



"In this Copernicus Sentinel-2 image, captured on 6 August 2022, the lake’s emerald green colour is likely due to the presence of phytoplankton. Streaks in the water, particularly visible in the west, indicate the presence of soil and sediments which have been stirred up by winds. Dark colored waters in the southern part of the lake indicate a presence of submerged and floating macrophytes (aquatic plants) as well as algae," says ESA.



"Surrounded by hills on three sides, Trasimeno is subject to heavy storms created by winds, especially from the north and west. There are three islets in the lake: Maggiore, Minore and Polvese (the largest). The lake’s shores are sparsely inhabited with only two popular villages: Castiglione del Lago and Passignano sul Trasimeno."



"Italy is experiencing its worst drought in 70 years which has affected drinking water supplies, hydroelectric power and agricultural production. High temperatures, hot winds and lack of rainfall are the main causes of drought in the Umbrian region which saw Lake Trasimeno’s drop 1.3 m, reaching the limit of the hydrometric zero in July 2022."



Video/Image Credit: ESA&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Lake Trasimeno in Central Italy

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> describes a new self-powered nanosensor that can instantly detect mercury contamination with the tap of a finger.&nbsp;



The oxidized form of mercury can be harmful when it is ingested through contaminated water or food. This makes it necessary for experts to develop sensors that can quickly and accurately detect the presence of mercury.&nbsp;



Zong-Hong Lin and colleagues have now created a triboelectric nanosensor (TENS) that can detect mercury by simply by touching a sample. According to the researchers, their TENS could serve as the basis for similar devices to safely and remotely monitor other pollutants.



Video Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Detecting mercury contamination with the tap of a finger

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Today’s Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> explores the ability of salt to transform the way that foods and beverages taste. Salt is known to cover up undesirable flavors, such as bitterness in coffee or beer, but how exactly does sodium chloride change the taste of other compounds?



One previous study showed that, not only does salt suppress bitterness, but also enhances sweetness and sourness. Another study revealed that bitterness reduction by salt seems to be happening at the tongue receptor level as well as in the brain.&nbsp;



While it is known that salt taste is mediated by the presence of sodium channels in the form of taste buds, experts believe that there is also an unknown receptor responsible for how we taste salt that has not yet been identified.&nbsp;



Video Credit: ACS Reactions



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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How does salt makes things taste better?

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Santiago, the capital city of Chile. The city is located in the center of the Santiago Metropolitan Region, which has a population of about eight million people.&nbsp;



'The weather of Santiago resembles the Mediterranean climate with dry and warm summers with temperatures reaching up to 35°C (from October to March) and cool and humid winters that can drop to 0°C (from April to September)."



"The city lies in the centre of the country’s central valley around 80 km from the Pacific Ocean to the west and borders Argentina to the east. A tiny part of Argentina is visible in the top-right corner of the image where the mountain crest of the Andes Mountains acts as a divider between the two countries," says ESA.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Santiago, Chile in South America

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Spiral,Galaxy,,Illustration,Of,Milky,Way

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Astronomers at <a href="https://www.jhu.edu/">Johns Hopkins University</a> have created an interactive map of the universe, including the actual position and real colors of 200,000 galaxies. The map allows the public to access data that was previously only available to scientists.



The map was developed using data collected by the Sloan Digital Sky Survey. For over two decades, a telescope in New Mexico was aimed at slightly different locations to capture the night sky.&nbsp;



"Growing up I was very inspired by astronomy pictures, stars, nebulae and galaxies, and now it's our time to create a new type of picture to inspire people," said map creator Brice Ménard, a professor at Johns Hopkins. "Astrophysicists around the world have been analyzing this data for years, leading to thousands of scientific papers and discoveries. But nobody took the time to create a map that is beautiful, scientifically accurate, and accessible to people who are not scientists. Our goal here is to show everybody what the universe really looks like."



"In this map, we are just a speck at the very bottom, just one pixel. And when I say we, I mean our galaxy, the Milky Way which has billions of stars and planets. We are used to seeing astronomical pictures showing one galaxy here, one galaxy there or perhaps a group of galaxies. But what this map shows is a very, very different scale."



"From this speck at the bottom, we are able to map out galaxies across the entire universe, and that says something about the power of science."



The <a href="https://mapoftheuniverse.net/">interactive map</a> is available online, where it can be downloaded for free.



Video Credit: Johns Hopkins&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Interactive map of the universe includes 200,000 galaxies

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Lesotho: Africa's "Kingdom in the Sky" Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features northwest Lesotho in South Africa.



According to ESA, Lesotho is the only nation in the world that lies completely above 1,000 m in elevation. The country is famous for its tall mountains and narrow valleys, and is known as Africa's "Kingdom in the Sky."



Out of a population of around two million people, about 80 percent live in rural areas. More than 75 percent of these people are engaged in <a href="https://www.earth.com/news/climate-change-will-have-a-global-impact-on-agriculture/">agriculture</a>, including rainfed cereal production and animal grazing.&nbsp;



ESA reports that the country’s agricultural system faces a growing number of issues, with climate-related vulnerabilities such as drought, floods and extreme temperatures occurring more frequently. 



Diamonds are amongst the minerals found in the mountains. Indeed, Lesotho can truly be called the Kingdom in the Sky. Beautiful, culturally rich, safe, affordable, and easily accessible from Durban and Johannesburg, mountainous Lesotho is a vastly underrated travel destination. the Kingdom of Lesotho (Sotho: 'Muso oa Lesotho) is an enclaved country in southern Africa. It is just over 30,000 km2 (11,583 sq mi) in size and has a population of around 2 million.



Video Credit: ESA&nbsp;&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer 



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Lesotho: Africa's "Kingdom in the Sky"

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Dublin, the capital and largest city of Ireland. Beyond its pub culture, Dublin is known as a modern culinary destination and a UNESCO City of Literature.



"Dublin is located near the midpoint of Ireland’s east coast in the province of Leinster. The city, which covers an area of around 115 square kilometers, is bordered by the Dublin Mountains, a low mountain range to the south, and is surrounded by flat farmland to the north and west," says ESA.



"The city straddles the River Liffey, which rises in the Wicklow Mountains and flows around 80 kilometers eastwards through the city of Dublin, in which it is canalised and bordered with quays. It then empties into Dublin Bay, an arm of the Irish Sea."



Dublin has an abundance of green spaces, including one of the largest enclosed public parks in any European capital city. Phoenix Park, which was originally formed as a royal hunting park in the 1660s, includes 707 hectares of green space.



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The city of Dublin on Ireland's east coast

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the province of Zaragoza in northeast Spain. The image was captured by the Copernicus Sentinel-2 mission.



"Together with the provinces of Huesca and Teruel, Zaragoza formed the old kingdom of Aragon. Its capital, also called Zaragoza (not visible in this image) is home to around half of Aragon’s population," says ESA.



"The Ebro River can be seen winding its way through the province from west to east in this image. Between its source in the Cantabrian Mountains in the northwest and its delta on the Mediterranean coast, the Ebro River is fed by more than 200 tributaries as it flows 910 km across much of northern Spain."



Since rainfall is very scarce in this region, irrigation in the Ebro basin is critically important. In the valleys surrounding the Ebro River, many fields are used for growing crops such as corn, wheat, and barley.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The province of Zaragoza in northeast Spain

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> reveals the evolution of the Columbia Glacier in southeastern Alaska. Columbia is among the fastest shrinking glaciers in the world, and the video documents its rapid retreat over the years.&nbsp;



Columbia Glacier is a large, multi-branched calving glacier that flows out of the Chugach Mountains to the Prince William Sound.&nbsp;



According to USGS, Columbia had a long history of stability prior to 1980, with a length 41 miles, and small, short-lived advances or retreats.



In the years since 1980, however, satellite images have captured Columbia’s alarming retreat. By using false-color images, scientists can distinguish between snow and ice, open water, vegetation, and rocky debris on the glacier’s surface.



The series of false-color images featured in today's video were acquired over the span of 35 years. You can see that by 2021, the glacier’s main branch had retreated about 15 miles from its initial position.



The Columbia Glacier has also lost more than 50 percent of its volume, mostly due to calving. <a href="https://www.earth.com/video/nasa-reveals-3d-visual-of-an-atmospheric-river/">NASA</a> reports that while climate change likely started the retreat, mechanical processes kept the disintegration going.



The NASA images are provided by Jesse Allen, Robert Simmon, Joshua Stevens, and Lauren Dauphin using data from Landsat satellites, from the U.S. Geological Survey, and data from MODIS on NASA’s Terra satellite. The structure of Columbia’s moraine played a large role in the stability of the glacier before 1980. 



Like other tidewater glaciers, the Columbia built up a moraine over time, and the mixture of ice and rock functioned like a dam keeping out the sea. It was supported on one end by the shoreline and by the underwater terminal moraine at the other.



Video Credit: NASA Earth Observatory/&nbsp; NASA’s Scientific Visualization Studio



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The rapid retreat of the Columbia Glacier

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the Pyrenees Mountains, which form a natural boundary between France and Spain in southwest Europe.



The mountain range is 430 kilometers in length. It stretches from the Mediterranean Sea on the east to the Atlantic Ocean on the west.



At an elevation of 3404 meters, Pico de Aneto is the highest mountain peak in the Pyrenees, and the third-highest peak in Spain. Pico de Aneto is located in the Posets-Maladeta Natural Park, which spans more than 82,000 acres.&nbsp;



"Geological studies have revealed that the Pyrenees Mountains have been around for longer than the Alps, with their sediments first deposited in coastal basins during the Paleozoic and Mesozoic eras," reports ESA.



"The entire mountain range formed due to the upwelling of large sedimentary rocks by the collision of the Iberian and the Eurasian plate around 100 to 150 million years ago, followed by intense erosion from ice and water."



The western Pyrenees receive more precipitation due to moisture blowing in from the Atlantic Ocean. The mountain range contains many lakes, several small glaciers, and some of the highest waterfalls in Europe.



Video &amp; Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The Pyrenees Mountains in southwest Europe

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Earth,Like,Exoplanet,3d,Render

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes two exoplanets that are orbiting a star 218 light-years away. A team of researchers led by the University of Montreal has found evidence that these planets are "water worlds."



The experts used data from NASA’s Hubble and Spitzer Space Telescopes. They discovered that exoplanets Kepler-138 c and Kepler-138 could be composed largely of water.



"We previously thought that planets that were a bit larger than Earth were big balls of metal and rock, like scaled-up versions of Earth, and that's why we called them super-Earths," explained study co-author Björn Benneke.&nbsp;



"However, we have now shown that these two planets, Kepler-138 c and d, are quite different in nature and that a big fraction of their entire volume is likely composed of water. It is the best evidence yet for water worlds, a type of planet that was theorized by astronomers to exist for a long time."



Video Credit: NASA Goddard



Image Credit: NASA, ESA, and Leah Hustak (STScI)



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Two distant planets may be "water worlds"

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Satellites reveal how Earth's systems are interconnected Today’s Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes Earth’s interconnected systems, and how this network is affected by rising temperatures.&nbsp;



During 2020, average global temperatures matched the hottest year on record. The hurricane season was also record-breaking, with many of the storms intensifying at extraordinary speeds. Hot water in the ocean is fuel for hurricanes. The satellite data shows that it's all one interconnected system showing how Satellites reveal how Earth's systems are interconnected.



According to NASA, dust swept up from Northern Africa plays a major role in the formation of hurricanes, and is also a key source of fertilization in the Amazon rainforest. As a result of<a href="https://www.earth.com/news/seagrass-wasting-disease-is-fueled-by-climate-change/"> climate</a> change, dust plumes are expected to decline, which will have an effect on vegetation far away.&nbsp;



Images from Earth-observing satellites show how the world’s plant life is affected by natural disasters, fires, and deforestation. Satellites also reveal how widespread changes in vegetation impact waterways,&nbsp; the climate, air quality. Satellites communicate by using radio waves to send signals to the antennas on the Earth. "Earth From Space" is a groundbreaking two-hour special that reveals a spectacular new space-based vision of our planet. 



Video Credit: NASA Goddard&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Satellites reveal how Earth's systems are interconnected

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Today’s Video of the Day from the <a href="https://welcome.miami.edu/">University of Miami</a> Rosenstiel School of Marine and Atmospheric Science explores how changes in water temperatures have affected tiger shark habitats and movements in the North Atlantic Ocean. The study reveals that rising temperatures have caused the sharks to shift toward the poles over the past 40 years.



“Tiger shark annual migrations have expanded poleward, paralleling rising water temperatures,” explained study lead author Neil Hammerschlag. “These results have consequences for tiger shark conservation, since shifts in their movements outside of marine protected areas may leave them more vulnerable to commercial fishing.”



The researchers analyzed nine years of tracking data from satellite-tagged tiger sharks, combined with four decades of conventional tag and recapture data provided by National Oceanic and Atmospheric Administration (NOAA) Cooperative Shark Tagging Program.



The experts found that during the last decade of record heat, for every one-degree Celsius increase in water temperatures, tiger sharks migrated further poleward by over 400 kilometers. They also migrated two weeks earlier than usual to waters off the northeastern coast of the United States.



“Given their role as apex predators, these changes to tiger shark movements may alter predator-prey interactions, leading to ecological imbalances, and more frequent encounters with humans,” concluded Professor Hammerschlag.



Video Credit: University of Miami Rosenstiel School of Marine and Atmospheric Science



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Tiger sharks are shifting poleward as temperatures rise

Today’s Video of the Day from the University of Miami...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> is focused on the melt ponds that emerge during the spring and summer on the Greenland Ice Sheet, which is the largest ice mass in the northern hemisphere.



"Melt ponds are vast pools of open water that form on both sea ice and ice sheets and are visible as turquoise-blue pools of water in this Copernicus Sentinel-2 image," says ESA.



"When snow and ice melts atop glaciers, water flows in channels and streams and collects in depressions on the surface. These melt ponds can speed up the melting of the surrounding ice since they greatly reduce the ice’s ability to reflect sunlight."



"This can create a positive feedback where an increasing number of melt ponds absorb more heat which causes ice cover to melt even faster."



According to ESA, Greenland has been hit with a late-season heatwave that began in early September. This caused the type of melt event that usually occurs in the middle of summer.



"In a recent paper published in Nature Climate Change, scientists found that major sea-level rise from the melting of the Greenland ice cap is now ‘inevitable’ even if the burning of fossil fuels were to halt overnight," says ESA. "Using satellite observations of Greenland ice loss and ice cap from 2000 to 2019, the team found the losses will lead to a minimum rise of 27 cm regardless of climate change."



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Melt ponds on the Greenland Ice Sheet

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes a new map of Mars that is providing insight into the planet’s watery past. The map also reveals where future missions could safely land on Mars.&nbsp;



The map has been created over the last decade using observations of water-rich rocks and mineral deposits. The images were captured by ESA’s Mars Express and NASA’s Mars Reconnaissance Orbiter.



"A big surprise is the prevalence of these minerals, with the map revealing hundreds of thousands of water-affected locations in the oldest parts of the planet," says ESA. "The new data will help answer exciting questions about Mars’ climate history, whether water was globally persistent or confined to short, intense episodes, and whether the conditions were ever suitable for life."



"Specifically, the map shows the locations and abundances of aqueous minerals. These are from rocks that have been chemically altered by the action of water in the past, and have typically been transformed into clays and salts."



According to John Carter of the Institut d’Astrophysique Spatiale (IAS), our collective understanding of Mars has been oversimplified. He explained that planetary scientists have tended to think that only a few types of clay minerals on Mars were created during its wet period, then as the water gradually dried up, salts were produced across the planet.



The new map shows that the composition of Mars is much more complicated than what we thought. For example, while many salts formed after Martian clays, there are some salts that are presumed to be older than some of the clays.&nbsp;



“The evolution from lots of water to no water is not as clear cut as we thought, the water didn’t just stop overnight. We see a huge diversity of geological contexts, so that no one process or simple timeline can explain the evolution of the mineralogy of Mars. That’s the first result of our study. The second is that if you exclude life processes on Earth, Mars exhibits a diversity of mineralogy in geological settings just as Earth does,” said Carter.



Video Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The history of Mars is much more complex than we thought

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Today's Video of the Day from the <a href="https://www.stowers.org/">Stowers Institute for Medical Research</a> describes how cavefish adapted to a sedentary lifestyle over tens of thousands of years. 



The experts found that the muscle metabolism of cavefish has been genetically reprogrammed over time. As a result, the animals have experienced major changes in their morphology and behavior. Despite these changes, however, the cavefish remain healthy and fit.



The research may provide new clues about the evolutionary consequences of prolonged physical inactivity in humans.&nbsp;



“It’s no surprise that people are moving less and less as technology has advanced,” said Rohner. “With cavefish, we have a unique system where we can study what might happen if people remained couch potatoes over very, very long periods of time.”



Video Credit: Stowers Institute for Medical Research



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Cavefish are healthy despite their sedentary lifestyle

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> some of the most incredible waves in the world, as seen by Landsat satellites.



"With more than 370,000 miles of coastline on Earth, there are plenty of places where epic waves build up, curl over, and hurtle toward the shore.- much to the thrill of surfers," says NASA. "There are some places where these waves are so magnificent that they can be seen from space."



"With the broad perspective of satellites, we can see how these iconic waves develop into the world’s tallest, longest, fastest, and heaviest."



Video Credit: NASA Earth Observatory&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Satellites capture the world's biggest and fastest waves

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