<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features the Bermejo River and the Río Grande de Tarija, which flow through Argentina and Bolivia in South America. The photograph was captured by an astronaut onboard the International Space Station.</p>



<h2 class="wp-block-heading" id="h-meandering-rivers">Meandering rivers</h2>



<p>“The meandering rivers in this image are sourced in the Andes Mountains and generally flow southeast through valleys in the foothills - the region between the high mountains and plains. The Iruya River deposits particles of silt and clay as it flows into the valley centered in this image,” said NASA.</p>



<p>“Visible indications of the rivers’ shifting channels include river islands, point bars (on the inside curve of streams), and several meander scars. Such scars form when a river gets cut off from the main flow and fills in with sediment, soil, and vegetation.”</p>



<p>“Sediment from the adjacent highlands filled valleys that were formed by tectonic forces driving uplift of the Andes. These deposits are subsequently carried by rivers, such as the Iruya, along with new sediment to form the light-toned braided channels and the adjacent darker-toned floodplains. Nutrient-rich floodplain soils provide fertile ground for agricultural fields.”</p>



<h2 class="wp-block-heading" id="h-bermejo-river">Bermejo River</h2>



<p>The Bermejo River originates in the Bolivian <a href="https://www.earth.com/news/biodiversity-hotspots-are-shrinking-in-the-andes-mountains/" target="_blank" rel="noreferrer noopener">Andes</a> and flows into Argentina. It plays a crucial role in the geographical and ecological landscape of the region. The river's course is characterized by its meandering path through the Gran Chaco plain, making it a significant river in the region's hydrological system.</p>



<h3 class="wp-block-heading" id="h-economic-importance">Economic importance</h3>



<p>The Bermejo River is vital for agriculture, providing essential water resources for irrigation. It also has potential for hydroelectric power generation.</p>



<h3 class="wp-block-heading" id="h-biodiversity-nbsp">Biodiversity&nbsp;</h3>



<p>The diverse habitats created by the Bermejo River, including its riverbanks, floodplains, and adjacent forests, support rich biodiversity. However, the wildlife in this region faces threats from habitat destruction, pollution, and climate change, making conservation efforts critical for their survival.</p>



<p><a href="https://www.earth.com/news/jaguars-in-the-amazon-are-threatened-by-climate-extremes/" target="_blank" rel="noreferrer noopener">Jaguars</a> are the apex predators of this region, and are occasionally spotted along the riverbanks, where they hunt. Large, herbivorous mammals called tapirs are found in the forests around the Bermejo River. They often visit the river to drink and cool off.</p>



<p>Capibaras, the world’s largest rodents, are commonly found in the wetlands and along the river edges.</p>



<p>The tallest flying bird found in South and Central America, jabirus can often be seen in wetlands along the Bermejo River. Toco toucans, known for their colorful bills, can be found in the forested areas near the river.</p>



<h2 class="wp-block-heading" id="h-rio-grande-de-tarija">Río Grande de Tarija</h2>



<p>The Río Grande de Tarija, also known in its lower stretches as the Guadalquivir, flows primarily within Bolivia. It is a critical watercourse in the Tarija Department, contributing significantly to the region's agriculture and livelihoods.</p>



<h3 class="wp-block-heading" id="h-economic-importance-0">Economic importance</h3>



<p>This river is essential for irrigation, supporting a variety of crops and contributing to the local economy. The surrounding lands are fertile and productive, thanks to the river's water.</p>



<h3 class="wp-block-heading" id="h-challenges">Challenges</h3>



<p>Similar to other rivers, the Río Grande de Tarija faces challenges such as water management issues, <a href="https://www.earth.com/news/predicting-the-effects-of-pollutants-on-river-ecosystems/" target="_blank" rel="noreferrer noopener">pollution</a>, and the impacts of climate change on its flow and health.</p>



<h3 class="wp-block-heading" id="h-wildlife-in-bolivian-rivers">Wildlife in Bolivian rivers</h3>



<p>River basins in Bolivia are home to a wide range of bird species, including various species of herons, egrets, kingfishers, and perhaps even some rarer species like the wattled jacana or the sunbittern. The diverse birdlife is attracted to the abundance of fish and the relatively untouched natural habitats along the river.</p>



<p>The Characidae family includes many fish species that are commonly found in South American rivers, such as tetras. They are known for their diversity and are a key part of the river's ecosystem, serving as both <a href="https://www.earth.com/news/diving-to-extremes-predatory-fish-frequent-the-oceans-twilight-zone/" target="_blank" rel="noreferrer noopener">predator</a> and prey.</p>



<p>Cichlids are another diverse group of fish that can be found in South American rivers. They are appreciated by aquarium enthusiasts worldwide and play significant roles in their ecosystems as both predators and herbivores.</p>



<p>The rivers of Bolivia are also home to various catfish species, which are well adapted to life in muddy and turbulent waters. These include the armored catfish, which are often found clinging to rocks and logs.</p>



<p>Image Credit: NASA Earth Observatory/ ISS Crew Earth Observations Facility/ Earth Science and Remote Sensing Unit, Johnson Space Center</p>



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<h3 class="wp-block-heading" id="h-nbsp">&nbsp;</h3>

The Río Grande de Tarija and Bermejo River in South America

Today's Image of the Day from NASA Earth Observatory features...

<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features the delta of the Ebro River on the northeast coast of Spain, captured by the Copernicus Sentinel-2 mission.</p>



<h2 class="wp-block-heading" id="h-ebro-river">Ebro River</h2>



<p>“Stretching across 910 km of northern Spain, the Ebro River is the second-longest river in the Iberian Peninsula. In the image, it can be seen as a green line winding its way through the peninsula before flowing into the Mediterranean, shaping the Ebro Delta,” noted ESA.</p>



<p>“The Ebro River discharges more water into the sea than any other river in Spain. As suspended sediment flows from the river’s mouth, it tints the coastal waters with a turquoise hue.”</p>



<h2 class="wp-block-heading" id="h-ebro-delta">Ebro Delta</h2>



<p>The Ebro Delta is one of the largest <a href="https://www.earth.com/news/wetland-methane-emissions-have-surged-at-high-latitudes/">wetland areas</a> in the western Mediterranean region. The river's basin is the largest in Spain, covering about 85,000 square kilometers.</p>



<h2 class="wp-block-heading" id="h-historical-significance-nbsp">Historical significance&nbsp;</h2>



<p>Historically, the Ebro River has been significant in numerous battles, including the famous Battle of the Ebro during the Spanish Civil War, which was one of the war's longest and deadliest conflicts.&nbsp;</p>



<h2 class="wp-block-heading" id="h-economic-significance-nbsp">Economic significance&nbsp;</h2>



<p>Economically, the Ebro plays a crucial role in agriculture, particularly in regions like La Rioja and Navarre, which are known for their vineyards. Additionally, the river supports various industries and hydroelectric power generation.</p>



<h2 class="wp-block-heading" id="h-ecological-significance">Ecological significance</h2>



<p>The Ebro Delta is ecologically rich, providing habitat for diverse bird species. It is also a vital area for rice cultivation in Spain.&nbsp;</p>



<h3 class="wp-block-heading" id="h-nature-reserve">Nature reserve</h3>



<p>“Most of the delta comprises the Ebro Delta Nature Reserve. With its protected wetlands, beaches, marshes, salt pans and estuaries, this reserve provides a natural habitat for numerous migratory birds and waterfowl,” said ESA.</p>



<h3 class="wp-block-heading" id="h-environmental-challenges-nbsp">Environmental challenges&nbsp;</h3>



<p>The river and its delta face environmental challenges such as pollution, water extraction for irrigation, and the impacts of <a href="https://www.earth.com/news/climate-change-may-have-altered-river-flow-worldwide/">climate change</a>, which threaten its ecosystem and the sustainability of its water resources.</p>



<h2 class="wp-block-heading" id="h-the-northeast-coast-of-spain">The northeast coast of Spain</h2>



<p>The northeast coast of Spain is a vibrant and diverse region, characterized by its rich history, unique culture, and stunning landscapes. </p>



<p>It includes the autonomous communities of Catalonia, which features the dynamic city of Barcelona, and part of the Valencian Community. This area is also part of what is known as the Costa Brava, which stretches from the town of Blanes up to the French border.</p>



<h3 class="wp-block-heading" id="h-geography">Geography</h3>



<p>The <a href="https://www.earth.com/news/human-activity-impacts-97-percent-of-the-worlds-coastline/">coastline</a> is renowned for its rugged beauty, with rocky cliffs, secluded coves, and small beaches. The interior regions feature mountains such as the Pyrenees, which offer skiing in winter and hiking in the summer.</p>



<h3 class="wp-block-heading" id="h-cultural-heritage">Cultural heritage</h3>



<p>The area has a strong cultural identity, particularly in Catalonia, where there is a significant movement for independence. The Catalan language is widely spoken alongside Spanish. The region is also known for its festivals, architecture (notably the works of Antoni Gaudí in Barcelona), and traditional dances like the Sardana.</p>



<h3 class="wp-block-heading" id="h-cuisine">Cuisine</h3>



<p>The cuisine is a delightful mix of fresh seafood from the Mediterranean, traditional Catalan dishes like "pa amb tomàquet" (bread with tomato), and rice dishes such as paella in the Valencian region. The area is also famous for its wines, including the sparkling wine Cava.</p>



<h3 class="wp-block-heading" id="h-tourism">Tourism</h3>



<p>The northeast coast attracts millions of tourists each year due to its beautiful beaches, historical sites, and vibrant cities. Barcelona, in particular, is a major tourist destination with attractions like the Sagrada Familia, Park Güell, and the bustling La Rambla.</p>



<h3 class="wp-block-heading" id="h-economy">Economy</h3>



<p>The economy of the northeast coast is one of the most dynamic in Spain, with Barcelona serving as a major hub for trade, education, entertainment, and technology.</p>



<p>Image Credit: NASA Earth Observatory</p>



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The Ebro River on the northeast coast of Spain

<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features the United Arab Emirates, where a slow-moving storm system dumped more than a year's worth of rainfall in just a few hours. </p>



<p>“The UAE’s National Center for Meteorology reported that eastern parts of the country measured up to 250 millimeters (10 inches) of rain in less than 24 hours. UAE, known for its dry desert climate, receives only about 140 to 200 millimeters (5.5 to 8 inches) of rainfall per year,” said NASA.</p>



<p>“Dubai International Airport recorded 119 millimeters on April 16, which is 1.5 times its typical annual rainfall. The deluge temporarily halted flights at the airport, which is among the world’s busiest for international travel.”</p>



<h2 class="wp-block-heading" id="h-heaviest-rainfall-on-record-in-the-united-arab-emirates-nbsp">Heaviest rainfall on record in the United Arab Emirates&nbsp;</h2>



<p>Authorities noted that this was the heaviest <a href="https://www.earth.com/news/record-heat-fueled-unexpected-and-deadly-storms-in-2023/" target="_blank" rel="noreferrer noopener">rainfall</a> on record in the United Arab Emirates. The news agency WAM called it a historic weather event that surpassed “anything documented since the start of data collection in 1949.”&nbsp;</p>



<p>“Heavy rain triggered flash flooding across eastern parts of the country, inundating roads and disrupting transportation,” said NASA. “The system first hit Oman on April 14 and continued to batter the UAE through most of the day on April 16.”&nbsp;</p>



<p>At least 18 people were killed in the <a href="https://www.earth.com/news/heavy-rainfall-events-in-the-northeast-are-set-to-increase-by-over-50-percent/" target="_blank" rel="noreferrer noopener">heavy rains</a> in Oman, including ten children that were swept away in a vehicle with one adult, according to a statement from the country’s National Committee for Emergency Management.&nbsp;</p>



<h2 class="wp-block-heading" id="h-strong-low-pressure-system">Strong low-pressure system</h2>



<p>Michael Mann, a climate scientist at the University of Pennsylvania, noted that three low-pressure systems formed a train of <a href="https://www.earth.com/news/thunderstorms-are-becoming-more-intense-due-to-climate-change/" target="_blank" rel="noreferrer noopener">storms</a> slowly moving along the jet stream - the river of air that moves weather systems - toward the Persian Gulf.&nbsp;</p>



<p>“The strong low-pressure system delivered multiple rounds of high winds and heavy rain to the northern and eastern parts of the country,” said NASA. “Some areas remained flooded on April 19, when Landsat 9 passed over the region for the first time since the storms.”&nbsp;</p>



<p>Climate experts attribute such extreme weather events to <a href="https://www.earth.com/news/limiting-global-warming-to-1-5-degrees-celsius-would-save-billions-of-lives/" target="_blank" rel="noreferrer noopener">global warming</a>. According to a report from Reuters, researchers anticipate that climate change will lead to hotter temperatures, increased humidity, and a greater risk of <a href="https://www.earth.com/news/seeking-ways-to-prevent-flooding-caused-by-climate-change/" target="_blank" rel="noreferrer noopener">flooding</a> in parts of the Gulf region. “Countries like the UAE where there is a lack of drainage infrastructure to cope with heavy rains can suffer the most,” the report stated.&nbsp;</p>



<h2 class="wp-block-heading" id="h-more-about-the-united-arab-emirates-nbsp">More about the United Arab Emirates&nbsp;</h2>



<p>The United Arab Emirates (UAE) is a federation of seven emirates located on the eastern side of the Arabian Peninsula. It borders Oman and Saudi Arabia, and has maritime borders with Iran and Qatar in the Persian Gulf. Established as a federation in 1971, the UAE has rapidly developed into one of the most modern and wealthy nations in the world, largely thanks to its vast oil and natural gas reserves.</p>



<p>Abu Dhabi serves as the capital and is the largest emirate, both in terms of land area and economy, largely because it holds the majority of the UAE's oil reserves. Dubai is the most populous city and is renowned globally for its spectacular skyscrapers, including the Burj Khalifa, the tallest building in the world, as well as its bustling ports, and vibrant tourism and shopping sectors.</p>



<p>The UAE has a diverse and multicultural society with a significant expatriate population, drawn by business opportunities and the tax-free living in many sectors. The official language is Arabic, though English is widely spoken, especially in business and educational settings.</p>



<p>Politically, the UAE is a federal absolute monarchy. It is governed by a Supreme Council of Rulers made up of the seven emirs, who appoint the prime minister and the cabinet. The country has made significant strides in terms of infrastructure and healthcare, and it continues to invest heavily in various sectors including renewable energy, education, and technology.</p>



<p>Culturally, the UAE balances its rapid modernization with a strong commitment to traditional Arab culture. The heritage of the desert Bedouin lifestyle is celebrated with falconry, camel racing, and traditional dance remaining integral to its cultural festivities. The nation is also a major hub for international arts and sports events, enhancing its global profile and cultural footprint.</p>



<p>Image Credit: NASA Earth Observatory&nbsp;</p>



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Storms dumped record rainfall in the United Arab Emirates

<p>Today's <strong>Image of the Day</strong> from the <a href="https://www.esa.int/" target="_blank" rel="noreferrer noopener">European Space Agency </a>features the barred spiral galaxy NGC 3783, which is located about 130 million light-years away in the constellation Centaurus. NGC 3783 is also the most prominent of a galaxy group (by the same name) that contains 47 <a href="https://www.earth.com/news/james-webb-captures-galaxies-that-are-too-old-to-exist/" target="_blank" rel="noreferrer noopener">galaxies</a>. </p>



<h2 class="wp-block-heading" id="h-galaxy-groups">Galaxy groups</h2>



<p>“Like galaxy clusters, galaxy groups are aggregates of gravitationally bound galaxies. Galaxy groups, however, are less massive and contain fewer members than <a href="https://www.earth.com/news/titanic-galaxy-cluster-collision-defies-all-current-understanding-of-the-universe/" target="_blank" rel="noreferrer noopener">galaxy clusters</a> do: where galaxy clusters can contain hundreds or even thousands of constituent galaxies, galaxy groups do not typically include more than 50,” noted ESA.</p>



<p>“The Milky Way is actually part of a galaxy group, known as the Local Group, which contains two other large galaxies (Andromeda and the Triangulum galaxy), as well as several dozen satellite and dwarf galaxies.”</p>



<h2 class="wp-block-heading" id="h-hd-101274-a-blue-giant-star">HD 101274: A blue giant star</h2>



<p>The bright object that appears to the right of the galaxy is the star HD 101274. “The perspective in this image makes the star and the galaxy look like close companions, but this is an illusion. HD 101274 lies only about 1,530 light-years from Earth, meaning it is about 85 thousand times closer than NGC 3783,” explained ESA.&nbsp;</p>



<p>HD 101274 is part of the NGC 3766 cluster, which is sometimes referred to as the Pearl Cluster, an open cluster known for its richness in bright stars and its relatively young age.</p>



<p>HD 101274 is categorized as a blue giant star, characterized by its high temperature and luminosity. Blue giants are massive stars that have left the main sequence phase of stellar evolution and are burning helium or heavier elements in their cores. These stars are known for their short lifespans relative to smaller stars due to their rapid consumption of nuclear fuel.</p>



<p><a href="https://www.earth.com/news/dark-stars-scientists-discover-a-new-type-of-star-powered-by-dark-matter/" target="_blank" rel="noreferrer noopener">Stars</a> like HD 101274 are important for astronomers because they help in studying the properties of stellar populations in clusters and the dynamics of stellar evolution in different environments. The spectral and photometric observations of such stars can provide valuable insights into the characteristics of their atmospheres, internal structures, and the processes occurring within and around them.</p>



<h2 class="wp-block-heading" id="h-bright-central-region-of-ngc-3783">Bright central region of NGC 3783</h2>



<p>One of the most interesting aspects of NGC 3783 is that it harbors an active galactic nucleus, meaning its central region is exceptionally luminous, likely due to the presence of a supermassive black hole. This black hole is actively accreting material, which emits a substantial amount of radiation as it spirals inward and heats up.</p>



<p>This galaxy is particularly known for its bright central region and has been studied extensively in the ultraviolet and X-ray light spectra to understand better the properties of the accretion disk around the black hole and the complex dynamics of the material surrounding it. These studies are crucial for understanding the physics of active galactic nuclei and the role they play in <a href="https://www.earth.com/news/galaxies-like-our-own-milky-way-are-not-unique/" target="_blank" rel="noreferrer noopener">galaxy evolution</a>.</p>



<p>According to ESA, NGC 3783 is a Type I Seyfert galaxy. “In this image it is recorded by Hubble in incredible detail, from its glowing central bar to its narrow, winding arms and the dust threaded through them, thanks to five separate images taken in different wavelengths of light," noted ESA.</p>



<p>“In fact, the galactic center is bright enough to Hubble that it exhibits diffraction spikes, normally only seen on stars such as HD 101274.”</p>



<h2 class="wp-block-heading" id="h-more-about-the-ngc-3783-galaxy-group">More about the NGC 3783 galaxy group</h2>



<p>The NGC 3783 group is part of the larger Hydra-Centaurus Supercluster, which itself is a massive collection of galaxies and galaxy clusters located primarily in the constellations of Hydra and Centaurus.</p>



<p>The NGC 3783 group consists of several galaxies that are gravitationally bound and interact with each other. These interactions can influence the galaxies' evolution through mechanisms like tidal forces and merger events, which can trigger star formation, fuel central black holes, and reshape the galaxies' structures.</p>



<p>Studying groups like the NGC 3783 group helps astronomers understand how <a href="https://www.earth.com/news/ceers-2112-ancient-galaxy-looks-strikingly-similar-to-ours/" target="_blank" rel="noreferrer noopener">galaxies</a> evolve together in a common gravitational environment, offering insights into the dynamics and evolution of structures on cosmic scales. This is especially relevant in understanding how galaxies influence each other through gravitational interactions and the environmental effects on galaxy evolution.</p>



<p>Image Credit: ESA/Hubble &amp; NASA</p>



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The luminous galaxy NGC 3783 and a blue giant star

Today's Image of the Day from the European Space Agency...

<p>Today's <strong>Image of the Day</strong> from <a href="https://earthobservatory.nasa.gov/" target="_blank" rel="noreferrer noopener">NASA Earth Observatory</a> features sediment swirling in the Gulf of Alaska on December 29, 2023.</p>



<p>"After an unusually snowy start to winter, southern Alaska’s coastline remained under a blanket of white in late December," said NASA.</p>



<p>"Meanwhile, greens and tans swirled in the dark blue water offshore. The dullness of the hues near shore suggests that the water is mostly colored by sediment. It is likely that phytoplankton - microscopic plant-like organisms - contributed to some of the hues farther from the coast."</p>



<p>According to NASA, much of the sediment in this region comes from “glacial flour” carried into the gulf by the Copper River.&nbsp;</p>



<p>"Glacial flour forms as glaciers move over bedrock and grind it into a fine silt. When suspended in water, glacial flour can make the water appear an opaque turquoise color - similar to phytoplankton blooms. The sediment carries iron and other nutrients that can spur the growth of these tiny marine organisms," explained NASA.</p>



<p>Aimee Neeley, a biological oceanographer at NASA’s Goddard Space Flight Center, noted that there are always phytoplankton in the water, but usually at lower levels in the wintertime at these latitudes.</p>



<p>The Gulf of Alaska is a vast and biologically rich body of water that lies at the northernmost part of the Pacific Ocean, encircled by Alaska.&nbsp;</p>



<p>The gulf extends approximately 1,500 miles from the Alaska Peninsula and the Aleutian Islands in the west to the Alexander Archipelago in the east.</p>



<p>Characterized by a subarctic climate, it's known for heavy rain and <a href="https://www.earth.com/news/sea-ice-loss-increases-snowfall-over-west-antarctica/">snowfall</a>. The region is also prone to frequent storms and is a significant pathway for colder northern weather patterns moving into the United States.</p>



<p>The Gulf of Alaska is home to a diverse marine ecosystem. It supports many species of fish, such as salmon and halibut, and is also a habitat for marine mammals like whales, sea lions, and seals.</p>



<p>The image was captured by the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument on NASA’s Aqua satellite.</p>



<p>Image Credit: NASA Earth Observatory&nbsp;</p>



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Sediment swirling in the Gulf of Alaska

<p>Historically, heavy rainfall has been considered the primary culprit for introducing contaminants into coastal waters. However, a recent study underscores the changing dynamics of water quality. Researchers found that "sunny day <a href="https://www.earth.com/news/seeking-ways-to-prevent-flooding-caused-by-climate-change/" target="_blank" rel="noreferrer noopener">flooding</a>," driven by rising sea levels, can also lead to increased levels of fecal bacteria, prompting a re-evaluation of water safety protocols.</p>



<h2 class="wp-block-heading" id="h-what-is-sunny-day-flooding">What is sunny day flooding?</h2>



<p>Sunny day flooding, also known as nuisance <a href="https://www.earth.com/news/extreme-floods-what-turns-a-rainstorm-into-a-catastrophe/" target="_blank" rel="noreferrer noopener">flooding</a> or high-tide flooding, occurs when high tides – often influenced by the moon's gravitational pull – rise higher than usual and inundate low-lying coastal areas. </p>



<p>This can include streets, storm drains, and even some properties. The key point here is that this flooding happens on days with clear skies and no rain.</p>



<p>The moon's gravitational pull exerts a significant influence on Earth's oceans, causing them to bulge outwards on the side closest to the moon and on the opposite side. These bulges create high tides, while the regions between them experience low tides. </p>



<p>Twice a month, during new and full moons, the gravitational forces of the sun and moon align, leading to particularly strong high tides known as spring tides.</p>



<h2 class="wp-block-heading" id="h-frequency-of-sunny-day-floods">Frequency of sunny day floods</h2>



<p>Sea levels are rising due to climate change, primarily caused by the burning of fossil fuels. This rising water level effectively raises the baseline for the ocean, meaning that even on days with normal high tides, water levels can reach higher than before, inundating areas that previously remained dry. This is why sunny day <a href="https://www.earth.com/news/100-year-floods-will-likely-be-annual-events-by-the-end-of-the-century/" target="_blank" rel="noreferrer noopener">flooding</a> events are becoming more frequent and severe.</p>



<p>While they may not be the dramatic, raging floods we typically picture, sunny day flooding events can still have significant consequences, as this study demonstrates. The floodwaters can overwhelm storm drains, leading to backups of potentially contaminated water.</p>



<h2 class="wp-block-heading" id="h-contamination-from-sunny-day-flooding">Contamination from sunny day flooding</h2>



<p>The new study by <a href="https://www.ncsu.edu" target="_blank" rel="noreferrer noopener">North Carolina State University</a> found that "sunny day <a href="https://www.earth.com/news/what-makes-some-plants-resistant-to-flooding/" target="_blank" rel="noreferrer noopener">flooding</a>" isn't just an inconvenience. These events introduce a range of contaminants into coastal waters, most notably fecal bacteria, raising concerns about potential health risks.</p>



<p>While these elevated bacteria levels typically dissipate within a few hours, scientists caution that the situation warrants attention. With rising sea levels, sunny day flooding is expected to become a more frequent and widespread issue, potentially leading to longer periods of water contamination. </p>



<h2 class="wp-block-heading" id="h-how-does-this-happen">How does this happen?</h2>



<p>“Historically we see the highest levels of fecal bacteria contamination in coastal waterways after it rains, because the rain washes contaminants into the waterways,” said Dr. Natalie Nelson, a lead researcher on the study.</p>



<p>Rising sea levels create a surprising issue: street flooding even on perfectly sunny days. High tides push water back up through stormwater systems. This causes shallow, contaminated puddles that are often dismissed.</p>



<h2 class="wp-block-heading" id="h-sunny-day-flood-bacteria">Sunny day flood bacteria</h2>



<p>To track just how bad these sunny day floods are, Dr. Nelson's team spent two summer months collecting daily water samples in coastal North Carolina. They were particularly interested in what happened during the "perigean spring tides" – super-strong tides due to the moon's position.</p>



<p>Sure enough, the floodwaters were contaminated. “We found that the floodwaters themselves had relatively high levels of fecal bacteria,” said Dr. Nelson. </p>



<p>The impact on larger coastal areas was not as clear. Sometimes the receding tide seemed to cause a spike in bacteria, but other times it didn't; and the spikes usually fizzled out within a few hours.</p>



<h2 class="wp-block-heading" id="h-public-health-and-safety">Public health and safety</h2>



<p>While your beach vacation likely isn't in jeopardy, there's still cause for concern. This study focused on a specific coastline, and water conditions can indeed vary. However, the fact that sunny day flooding led to any increase in bacteria highlights a potential risk that scientists like Dr. Nelson want to further investigate.</p>



<p>“Sea levels are going to continue rising for the foreseeable future. So we are definitely going to see more sunny day flooding, and those floods will be getting worse," said Dr. Nelson.</p>



<p>"We need to continue studying the impact that these tidal floods have on our water quality, because the more we understand, the better able we will be to make informed decisions about public health and safety.”</p>



<p>The next time you see street flooding on a sunny day, don't think "just seawater." Be mindful that the water is probably more polluted than it looks, especially for a few hours after the tide goes out. </p>



<p>While scientists are still figuring out the exact risks, it's good practice to avoid letting kids play in this water, and thoroughly rinse off any gear (or yourself) that comes into contact with it. </p>



<p>The study is yet another reminder of the complex ways that climate change can affect our everyday lives.</p>



<p>The study is published in the journal <em><a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GH001020" target="_blank" rel="noreferrer noopener">GeoHealth</a></em>.</p>



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Sunny day flooding increases fecal bacteria in coastal waters

Historically, heavy rainfall has been considered the primary culprit for...

<p>While many parents of preschool and elementary-aged children aim to provide balanced, nutritious <a href="https://www.earth.com/news/children-with-vegetarian-diets-maintain-similar-growth-and-nutrition/" target="_blank" rel="noreferrer noopener">diets</a>, certain strategies intended to promote healthy eating may not always produce the desired outcomes, according to insights from the University of Michigan Health C.S. Mott Children’s Hospital <a href="https://mottpoll.org/" target="_blank" rel="noreferrer noopener">National Poll on Children’s Health</a>.</p>



<h2 class="wp-block-heading" id="h-accommodation-to-children-s-diet-preferences">Accommodation to children’s diet preferences</h2>



<p>A significant finding from the report indicates that three in five parents will prepare different meals if their child rejects the family's meal choice, demonstrating a high level of accommodation to children’s preferences.</p>



<p>Additionally, the poll reveals that one in eight parents enforces a rule requiring children to finish everything on their plate.&nbsp;</p>



<h2 class="wp-block-heading" id="h-healthy-diets-for-children">Healthy diets for children</h2>



<p>Moreover, despite recognizing that the standard American diet, rich in saturated fats and sugars, is not ideal for children, only a small proportion of parents have explored alternative, potentially healthier diets at home.</p>



<p>“Feeding young children can be challenging due to general pickiness, hesitancy to try unfamiliar foods, and constantly evolving food preferences,” said Mott Poll co-director and Mott pediatrician Susan Woolford, M.D., emphasizing the crucial nature of early childhood as a period for establishing lifelong healthy eating patterns.&nbsp;</p>



<p>“Parents’ concern about whether their child is eating enough or if they’re getting the nutrients they need may lead them to adopt practices that actually sabotage their efforts to get kids to have healthy eating habits in the short and long term.”</p>



<h2 class="wp-block-heading" id="h-standard-american-diet-and-children-nbsp">Standard American diet and children&nbsp;</h2>



<p>The poll, based on responses from 1,083 parents of children aged 3-10 surveyed in February, provided a broad overview of parental beliefs and practices concerning their children's <a href="https://www.earth.com/news/humans-have-nutritional-wisdom-we-eat-what-our-body-needs/" target="_blank" rel="noreferrer noopener">nutrition</a>.</p>



<p>The results revealed that a third of parents believe the standard American diet is healthy compared to half who rank the Mediterranean higher in nutritional value. However, few have tried alternative diets for their child.</p>



<h2 class="wp-block-heading" id="h-excess-intake-of-calories">Excess intake of calories</h2>



<p>“Parents may recognize the standard diet in the U.S. includes high amounts of saturated fats, added sugars, sodium, and refined carbohydrates, which can generate an excess intake of calories beyond nutritional needs and contribute to health problems,” Woolford said.&nbsp;</p>



<p>“However, despite this recognition and evidence suggesting that other diet options may help avoid many illnesses, only about 9% have tried the <a href="https://www.earth.com/news/mediterranean-diet-keeps-the-brain-sharp-even-in-old-age/" target="_blank" rel="noreferrer noopener">Mediterranean diet</a> for their children and fewer have tried giving their children a vegetarian diet.”</p>



<h2 class="wp-block-heading" id="h-balanced-approach-to-children-s-diets">Balanced approach to children’s diets</h2>



<p>In addition, Woolford stressed the importance of ensuring that children receive sufficient nutrition when experimenting with diets that exclude certain food groups. For instance, diets that limit animal products need to incorporate alternative protein sources like meat substitutes, tofu, or legumes.</p>



<p>The poll also explored family dining rules, which can either promote or hinder a child's healthy diet. About fifteen percent of parents enforce a rule that children must finish what’s on their plate, potentially encouraging overconsumption, particularly if portion sizes are too large.</p>



<p>Woolford advocates for a more balanced approach: “Requiring children to eat everything on their plate, or withholding dessert unless all other foods are eaten, can lead to overconsumption, especially if portion sizes are too large for the child’s age.”</p>



<h2 class="wp-block-heading" id="h-offering-a-healthy-range-of-foods">Offering a healthy range of foods</h2>



<p>Instead, she supports a model where “parents provide, and the child decides.” This strategy involves parents offering a range of healthy foods and letting children decide which to eat and how much, thus respecting their natural hunger cues and preferences.</p>



<p>According to Woolford, sixty percent of parents prepare separate meals if their children reject what's served at mealtime, which often results in less nutritious alternatives.</p>



<p>“Rather than allowing the child to choose an alternate menu, parents should provide a balanced meal with at least one option that their child is typically willing to eat,” she advised.</p>



<p>Woolford also emphasizes the importance of parental modeling in dietary habits, noting that children often emulate the behaviors they observe. Moreover, avoiding snacks between meals is also likely to help children have a better <a href="https://www.earth.com/news/disadvantaged-stimulate-appetite/" target="_blank" rel="noreferrer noopener">appetite</a> and increase their willingness to eat offered foods.</p>



<h2 class="wp-block-heading" id="h-biggest-challenges-faced-by-parents-nbsp">Biggest challenges faced by parents&nbsp;</h2>



<p>The survey confirmed that parents often face significant challenges when it comes to ensuring their children eat a healthy diet. Key issues include dealing with picky eaters, the higher cost of nutritious food, and concerns about food waste. A smaller number of parents reported that time constraints make it difficult to prepare healthy meals.</p>



<h3 class="wp-block-heading" id="h-introducing-vegetables-nbsp">Introducing vegetables&nbsp;</h3>



<p>According to survey data, nearly all parents have attempted at least one strategy to encourage their children to eat vegetables, which includes daily servings, preparing vegetables in a way that appeals to their children, introducing new vegetables, and allowing children to choose vegetables during shopping.</p>



<p>Some parents also engage their children in the preparation of vegetables, incorporate vegetables into other dishes, or offer rewards for eating vegetables.&nbsp;</p>



<p>“Unsurprisingly, parents said pickiness and getting kids to eat veggies were among major challenges during mealtimes,” Woolford said. “Parents should try to include children in meal decisions, avoid pressuring food consumption and provide a variety of healthy options at each meal so kids feel more control.”</p>



<h3 class="wp-block-heading" id="h-portion-control">Portion control</h3>



<p>Portion control presents another difficulty for many parents, as properly sizing meals is crucial for preventing <a href="https://www.earth.com/news/childhood-obesity-rates-spiked-during-the-pandemic/" target="_blank" rel="noreferrer noopener">childhood obesity</a>. </p>



<p>The survey revealed that nearly 70% of parents serve their children slightly smaller portions than those given to adults, while others let children decide their portion sizes, rely on pre-measured portions, or serve children adult-sized portions.</p>



<p>To aid in appropriate portion sizing, Woolford recommends utilizing resources like the U.S. Department of Agriculture's “<a href="https://www.myplate.gov/" target="_blank" rel="noreferrer noopener">MyPlate</a>,” which offers visual guidelines for balancing food groups and managing portion sizes.</p>



<h2 class="wp-block-heading" id="h-identifying-unhealthy-food-options-at-the-grocery-store">Identifying unhealthy food options at the grocery store</h2>



<p>Grocery shopping is a critical starting point for healthy eating. Parents in the survey indicated that they limit their children's intake of foods with added sugars and processed ingredients. However, identifying unhealthy options can be challenging due to deceptive marketing.&nbsp;</p>



<p>“Parents should read labels, avoiding the marketing on the front of packages and focusing instead on the details on the back. They should pay particular attention to nutrition information and ingredient lists - especially if they’re long with unrecognizable items - as well as sodium, added sugars, and fat,” Woolford advises.</p>



<p>She also suggests making grocery shopping an educational and engaging activity for children. “Have them help in the process of choosing the healthiest options, not ones that necessarily directly advertise to children, but foods that they are willing to try that are lower in sugar, fat and salt,” she said.&nbsp;</p>



<p>“Spend most of the time in the produce section and try to make it fun by maybe selecting new options from different parts of the world that they haven't tried before.” This approach not only promotes healthy eating but also encourages children to explore and enjoy a variety of foods.</p>



<p>-----</p>



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Feeding children healthy diets can be very challenging

While many parents of preschool and elementary-aged children aim to...

<p>In the Solomon Islands, a team of scientists led by the <a href="https://www.unimelb.edu.au/" target="_blank" rel="noreferrer noopener">University of Melbourne</a> has identified a swift and unusual type of evolutionary change among local <a href="https://www.earth.com/news/evolutionary-secrets-how-bat-teeth-adapted-to-their-diverse-diets/" target="_blank" rel="noreferrer noopener">bat</a> populations. The experts suggest that two distinct groups of leaf-nosed bats, initially thought to be different species due to their significant size differences, are actually proof of a rare case of parallel evolution.</p>



<h2 class="wp-block-heading" id="h-different-sizes-similar-dna">Different sizes, similar DNA</h2>



<p>Although these two species share the same environment, they have independently developed similar traits. The smaller species, <em>Hipposideros diadema</em>, is widespread, inhabiting not only the Solomon Islands but also regions in Southeast Asia, Papua New Guinea, and northern Australia. In contrast, the larger species, named <em>Hipposideros dinops</em> or the Fierce Leaf-Nosed Bat in 1905, is exclusive to the Solomon Islands.</p>



<p>“Although they are very different sizes, the bats’ DNA is very similar. They use very different sonar frequencies, they probably eat different food, and even when they live in the same cave together they don’t interbreed. That is why no one has ever really questioned whether they were different species,” explained lead author Tyrone Lavery, a mammalogist at the University of Melbourne.&nbsp;</p>



<h2 class="wp-block-heading" id="h-rapid-evolution-of-larger-bodied-bats">Rapid evolution of larger-bodied bats</h2>



<p>According to the scientists, despite their independent origins, each group of larger bats has evolved to look the same, averaging more than double the weight of the small bat. “Our research suggests the rapid and repeated <a href="https://www.earth.com/news/vampire-bats-live-blood/" target="_blank" rel="noreferrer noopener">evolution</a> of larger bodied bats from smaller bats, each happening independently on separate islands,” said Lavery.</p>



<p>“When we created family trees using the bats’ DNA, we found that what we thought was just one species of large bat in the Solomon Islands was actually a case where bigger bats had evolved from the smaller species multiple times across different islands.”</p>



<h2 class="wp-block-heading" id="h-parallel-bat-evolution-nbsp">Parallel bat evolution&nbsp;</h2>



<p>This phenomenon of parallel evolution, where separated populations of the same species evolve similar traits in similar environments, is exceedingly rare and seldomly observed in real-time, especially among mammals.&nbsp;</p>



<p>The experts suggest that these larger bats might be evolving to exploit food sources not accessible to their smaller counterparts, although they are theoretically capable of <a href="https://www.earth.com/news/interbreeding-survival-early-elephants/" target="_blank" rel="noreferrer noopener">interbreeding</a>.</p>



<p>“Something very strong is pushing or selecting for these big bats, and it is strong enough for it to happen multiple times on different islands. We think these larger bats might be evolving to take advantage of prey that the smaller bats aren’t eating. Although they could probably interbreed, they don’t for some reason,” Lavery said.</p>



<h2 class="wp-block-heading" id="h-diverse-dietary-preferences-nbsp">Diverse dietary preferences&nbsp;</h2>



<p>The differences in sonar frequencies between the groups suggest diverse dietary preferences, with the larger bats likely targeting bigger prey such as larger insects or even <a href="https://www.earth.com/news/world-frog-day-addressing-environmental-threats-to-frogs/" target="_blank" rel="noreferrer noopener">frogs</a>. </p>



<p>The study, which included measuring 103 bat specimens from various international museums, confirmed no overlap in body size between the two groups, reinforcing their distinct developments despite genetic similarities.</p>



<h2 class="wp-block-heading" id="h-islands-and-bat-evolution">Islands and bat evolution</h2>



<p>According to Lavery, this pattern of parallel evolution in leaf-nosed bats has been observed in the Solomon Islands on Guadalcanal and in the Western Province, but more research is needed to see if the same pattern occurs on other islands.&nbsp;</p>



<p>“We may think of evolution as a very slow process, but it can happen rapidly when the conditions are right and two groups are separated and stop interbreeding. They can begin to evolve on different pathways,” he said.</p>



<p>“Islands are famous for helping us to observe and understand the processes for how species evolve in real time. They’re also places that are very vulnerable to the types of disturbance that humans create. It’s important that we look after these incredible landscapes in Solomon Islands before we lose these stories even before we find them,” he concluded.</p>



<h2 class="wp-block-heading" id="h-more-about-bat-evolution">More about bat evolution</h2>



<p>Bats represent a remarkable example of mammalian evolution, having developed unique adaptations that allow them to thrive across diverse environments globally. The evolution of bats is particularly notable for their development of flight and <a href="https://www.earth.com/news/bats-share-social-information-through-echolocation-calls/" target="_blank" rel="noreferrer noopener">echolocation</a>, which have played crucial roles in their ability to occupy ecological niches that other mammals cannot.</p>



<h3 class="wp-block-heading" id="h-early-bats">Early bats</h3>



<p>The fossil record suggests that bats first appeared at least 50 million years ago during the Eocene epoch. These early bats already possessed the wing structures necessary for flight, indicating that their ability to fly evolved quite rapidly in evolutionary terms.&nbsp;</p>



<p>This quick adaptation to flight is believed to have significantly contributed to their global spread and diversification.</p>



<h3 class="wp-block-heading" id="h-echolocation">Echolocation</h3>



<p>Echolocation, the ability to navigate and find food using sound waves, is another key evolutionary development in bats, although it is not universal among all bat species.&nbsp;</p>



<p>Echolocation likely developed after flight, with different bat species evolving this ability independently. This suggests a strong evolutionary pressure to optimize feeding strategies in dark environments, like night skies or dense forests.</p>



<h3 class="wp-block-heading" id="h-convergent-evolution">Convergent evolution</h3>



<p>Molecular studies have provided insights into bat phylogeny, showing that bats are divided into two main suborders: the largely <a href="https://www.earth.com/news/how-fruit-bats-suffer-no-consequences-from-their-high-sugar-diet/" target="_blank" rel="noreferrer noopener">fruit-eating</a> megabats and the echolocating microbats. </p>



<p>Interestingly, some megabats have also developed echolocation, albeit through different mechanisms than microbats, showcasing convergent evolution - where different species independently evolve similar traits.</p>



<h3 class="wp-block-heading" id="h-morphological-changes-and-diet">Morphological changes and diet</h3>



<p>Bats have also adapted to a wide range of dietary preferences, from insects and fruit to vertebrates and blood, each adaptation allowing bats to exploit new or underserved ecological niches. </p>



<p>These dietary adaptations are accompanied by morphological changes, such as tooth and jaw structure, digestive enzymes, and flight adaptations, enabling them to specialize and thrive.</p>



<p>The study is published in the journal <a href="http://dx.doi.org/10.1093/evolut/qpae039" target="_blank" rel="noreferrer noopener"><em>Evolution</em></a><em>.</em></p>



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Rare type of parallel evolution found in island bats

In the Solomon Islands, a team of scientists led by...

<p>[ooyala code=&#8221;w4ZXNlYjE63-n5oLv7n4SIU80rzHvmZu&#8221; player_id=&#8221;ce75157bc770441eaf5e849ae4d1d21f&#8221; auto=&#8221;true&#8221; width=&#8221;1920&#8243; height=&#8221;1080&#8243; autoplay=&#8221;true&#8221;]</p>
<p><span style="font-weight: 400;">How being in space affects the human immune system Today’s </span><b>Video of the Day</b><span style="font-weight: 400;"> comes from NASA and features a look at how being in space affects the human immune system. </span></p>
<p><span style="font-weight: 400;">Radiation, microgravity, stress, and altered <a href="https://www.earth.com/news/lack-sleep-eat-brain/">sleep</a> cycles are all factors that can affect the immune systems of astronauts spending an extended period of time in space. To learn more, just hit play! For the space program, called “chips in space,” a team led by Huh and Worthen aims to model a condition called immunosuppression bydeveloping an airway on a chip. Space travel weakens immune system and scientists have figured out why &#8230; exerts a dual effect on the human immune system, simultaneously dampening cytotoxic responses. </span></p>
<p>NASA studies are looking at the <strong>effects</strong> of space travel on the human body&#8217;s immune system. Life in space does strange things to the human body — itstretches the spine, it turns muscles to jelly<strong>,</strong> and now new research led by NASA shows that spaceflight confuses.  Space travel weakens our immune systems: Now scientists may know why. Microgravity in space perturbs human physiology and is detrimental for astronaut health. Among the possible causes of <strong>space</strong> flight-induced alterations in <strong>immune</strong> responses are exposure to microgravity, exposure to stress, exposure to radiation.</p>
<p><span style="font-weight: 400;">&#8212;</span></p>
<p><i><span style="font-weight: 400;">By </span></i><a href="mailto:rarnold@earth.com"><i><span style="font-weight: 400;">Rory Arnold</span></i></a><i><span style="font-weight: 400;">, </span></i><a href="https://www.earth.com/staff"><i><span style="font-weight: 400;">Earth.com</span></i></a></p>
<p><i><span style="font-weight: 400;">Source: </span></i><a href="https://science.nasa.gov/science-news/sciencecasts/your-immune-system-in-space"><i><span style="font-weight: 400;">NASA</span></i></a></p>
