Fracking sites found to negatively impact health of newborns
As hydraulic fracturing, or fracking, becomes more widely used across the United States, concerns are growing about the potential health and environmental consequences that may follow. New research reveals that there are health risks for babies born to mothers living within 2 miles of a hydraulic fracturing site.
The researchers found that mothers living within half of a mile from a drilling site were 25 percent more likely to give birth to an infant born at a low birth weight. This condition leaves babies at a greater risk of infant mortality, ADHD, asthma, lower test scores, and lower lifetime earnings.
Study co-author Janet M. Currie is a professor of Economics and Public Affairs at the Princeton University Woodrow Wilson School of Public and International Affairs.
“Given the growing evidence that pollution affects babies in utero, it should not be surprising that fracking, which is a heavy industrial activity, has negative effects on infants,” said Currie.
The research team analyzed records from over 1.1 million births in Pennsylvania between 2004 and 2013. They compared the outcomes of babies born to mothers living near a hydraulic fracturing site to those living farther away, taking into account when fracking began at specific sites.
The study revealed that mothers living within .6 miles of a fracking site were 25 percent more likely to have babies born under 5.5 pounds, which is considered low birth weight. This risk decreased by about half to one-third for women who resided between half a mile and 2 miles from a drilling site, while infants born to mothers living beyond 2 miles from a fracking site showed little to no impacts.
“As local and state policymakers decide whether to allow hydraulic fracturing in their communities, it is crucial that they carefully examine the costs and benefits, including the potential impacts from pollution,” said study co-author Michael Greenstone. “This study provides the strongest large-scale evidence of a link between the pollution that stems from hydraulic fracturing activities and our health, specifically the health of babies.”
The research is published in the journal Science Advances.
Deforestation in the Amazon is lowering fish yields
When tropical forests are converted to land for agricultural use, the result is less rain, more droughts, and deteriorating freshwater ecosystems. And now, surprising new research reveals that the clearing of tropical forests can also lead to negative changes in fish production.
Study lead author Leandro Castello is an assistant professor of Fisheries at Virginia Tech‘s College of Natural Resources and Environment. The researchers set out to investigate how deforestation along the Amazon River impacts fish yields.
“The conflict between raising cattle and managing fisheries is a concern that is shared with floodplain residents, but there had been no rigorous studies of how loss of forest affects the productivity of floodplain fisheries,” explained study co-author David McGrath.
Approximately one-third of the world’s wild-caught fish yield comes from tropical regions, and fisheries are critical to this production. The conditions of the area of land adjacent to a river, known as a floodplain, have a major impact on the success of fisheries.
“Floodplain forests can provide structures that protect fish and their offspring, and provide habitat for insects that many fish rely on for food,” said Castello. “Those forests also produce plant material on which fish may also feed.”
Using a study area of 1,000 square kilometers, the researchers collected data on fisheries yields over a 12-year time period. The team also created a map of the region’s 1,500 lakes and interviewed local fishermen about fish caught in different areas. By combining this data, the experts determined which areas yielded the most fish.
“We collected roughly 36,000 separate data points that were plotted in order to make a map of where the fish were coming from,” said Castello.
Satellite images from NASA allowed the researchers to collect a second data set on habitat features in the study region to examine whether the presence of floodplain forests impacted fish yields.
“Essentially, we wanted to know if fish yields in areas with forested floodplains are greater, the same, or less than areas where forests have been cut down,” explained Castello.
“Our results indicated that lakes with floodplain forests provided fishers with greater fish yields,” he said. “This allows us to infer that if you cut down the forests, fish yields in those lakes would decrease. Tropical deforestation is not only a terrestrial issue – it can also decrease the number of fish available to some of the world’s poorest populations.”
The researchers will continue to investigate what other factors affect fisheries yields, but the indications of this particular study are clear.
“You have to protect these habitats if you want to maintain the food production and the income that rivers provide,” said Castello. “If we don’t protect these areas, we lose the rivers and we lose the fish.”
The study is published online in the journal Fish and Fisheries.
Reducing emissions in the Middle East depends on private sector
Air pollution can cause a range of respiratory and cardiovascular diseases. In the Middle East and North Africa (MENA) region alone, approximately 125,000 people died due to air pollution-related diseases in one year.
The MENA region, like many parts of the world, could greatly benefit from policy changes meant to reduce greenhouse gas emissions.
However, according to a new study, expecting government intervention to combat pollution in this area may not be as effective as looking to private businesses to set an example and lead the way for greener solutions.
The study aims to provide better strategies for monitoring and reducing greenhouse emissions in the MENA region.
“Our review has shown that private businesses in the MENA region have been successful in leading initiatives that reduce emissions – for example, SaudiAramco is successfully supporting national emission monitoring in Saudi Arabia,” said Prashant Kumar, the Founding Director of the GCARE. “It would be a good initiative to encourage companies to lead such emission reduction efforts in the future.”
The study examined businesses that have adopted new methods or technologies that help reduce pollution and uses these as examples to show how private businesses can have a big impact.
Kumar notes that the MENA region is responsible for 4.5 percent of total greenhouse gas emissions worldwide
Within the Middle East and North Africa, the energy sector accounts for 38 percent of CO2 emissions, which is why the researchers recommend shifting financial focus from the energy sector to public transportation.
Improving public transportation and making it a greener and more energy efficient system could help reduce emissions, as public transportation is still a major contributor to CO2 emissions.
Private companies could lead the way in reducing emissions as waiting for government intervention could be a long and less than fruitful endeavor.
“It is not feasible to ask this resource-constrained region to step away from the energy sector, but a focus on improving public transport infrastructure, together with encouraging businesses to implement emission control measures could go a long way in reducing the deadly impacts of pollution on the public health,” said Kumar.
Earth.com exclusive: The Canyon Tree Frogs of Bear’s Ears
When I was in high school, my environmental science class took a small voluntary field trip after dark. At night we hiked up rough sand stone canyons dotted with scattered pools of water. We jumped over trickles and scrambled around boulders. Flashlights cut through the darkness everywhere. We made an enormous ruckus. The canyon tree frogs were singing back at us that night too. Unsurprisingly we heard but didn’t see a frog. Canyon Tree Frogs became something mysterious to me after that night; something wild and hidden.
Years later, again on the Colorado National Monument, I was hiking through desert canyon country. I was half catching insects for a college entomology class, half hiking for pleasure. Stopping near an ephemeral desert pool, I watched carefully for water insects. There were darting water beetles beneath the surface, water striders dancing on the top. In the bottom of the pool was also a cluster of small, gooey eggs: frog eggs. In my mind the eggs became Canyon Tree Frog Eggs. I briefly contemplated taking the eggs home and raising them in an aquarium to satisfy my curiosity. I changed my mind though, it would be illegal to take the eggs and I doubted my ability to raise them. The eggs remained a mystery.
This fall my girlfriend Erin and I drove out to Bear’s Ears National Monument. Bear’s Ears is a beautiful piece of desert. Burnt red stone out of a thousand westerns lines the horizon, yellowish stone canyons yawn at your feet. The place feels remote, alien, yet familiar; a dream landscape. We drove for an hour on dirt roads, rutted and punctuated with rock. We parked next to two other vehicles. In one vehicle, a family was getting ready to depart. The man told of finding pottery sherds that he left in the canyon and wondered if we knew of petroglyphs. We didn’t. The man and his wife sipped beer, their young daughter enthused on their trip. The family left; they were the last people we saw for three days.
The hike we chose in Bear’s Ears was Dark Canyon. Remote, wild, rugged, the canyon was both the good and the painful part of freedom. Scrambling down a steep canyon wall covered in scree, we walked broken fragments of crumbling trail. We lost the trail, only to find a small cairn leading us on, into the canyon. Cactus were everywhere, the few junipers were blessings of shade.
The bottom of the canyon was a maze of boulders and shrubs in a dry streambed. We were happy to have descended to the bottom. I still have two bruised toe nails from scrambling down the canyon. We were tired of the madness of carrying our Shih Tzu down class 3 terrain and let her down to sniff around boulders and walk. The trail from the bottom to our campsite wasn’t long.
We slept on the sand beneath a cottonwood tree. We could hear the constant mutterings of a stream by our heads. I thought sometimes I heard snippets of conversation but it was always the stream. Hiking just a little uphill from the stream we became enveloped in eerie silence. The canyon forked, calling us in too many directions for one trip. We pondered the idea of a month spent in this lonely spot.
The first morning, I stumbled towards the stream, empty coffee pot in hand, ready for the morning ritual. By the stream rested a small, greyish amphibian. Before I could stop, the frog leapt and neatly splashed into the stream. The frog swam to the bottom of the clear water and stopped; hiding. I watched for a few minutes and the frog didn’t move. Frogs are adapted to spend long periods of time underwater. Amphibians can even absorb small amounts of oxygen from water through porous skin. I filled my coffee pot and went back to camp.
I wandered down a canyon, quiet, bright, beautiful, a land of shade and sun, sand and rock. I found the tiny fossils of Crinoids or Sea Lilies embedded in stone. Sea Lilies still live in oceans today. I marveled at the beautiful opalescent quality of the fossils and the age and power of the earth. Parts of Utah were once ocean; they may again be ocean one day.
Back at camp there were more frogs near the stream, I got a better look at them. The frogs had long delicate toes ending in rounded cups. Their eyes were bright; a greyish color matching the skin. The frog’s skin was dotted with red specks. I had a growing realization, I looked in our field guide to confirm; these were Canyon Tree Frogs. The frogs swam in the stream, or sat on the banks. We only saw them in the late afternoon or early morning. Canyon Tree Frogs are nocturnal.
Recently Donald Trump ordered Bear’s Ears National Monument reduced in size by 85%. The move could open up thousands of acres to mining, to oil and gas, to ranching. The move is a blow to Native American groups, to environmentalists and everyone who loves the outdoors. The Canyon Tree Frog is not endangered. I won’t tell you that Canyon Tree Frogs may hold the cure for cancer or how many mosquitoes they eat. Canyon Tree Frogs are rather ordinary, easily missed, a small, rather cute frog. Canyon Tree Frogs are precious. Other people will tell you of Native American ruins, and fossils, or rare plants and animals. All of these things are important, they all deserve a fight. Why should you care about one frog? Isn’t the beauty of one frog worth a fight? What we stand to lose is mundane as well as magnificent. We may lose some artifacts. We may lose fossils or an endangered bird. We’ll also lose a lot of mundane things. We’ll lose the quiet sound of a stream alone in the desert. We may lose the desert smell of one juniper or the sticky taste of a piñon nut. We can lose a hundred small, insignificant individual animals. We may lose the croaking, splashing, swimming of half a dozen frogs in a remote desert canyon.
If we give Trump even the life of one frog or a hundred, we’ve given too much. We stand to lose so much more. Others will remember Bears Ears in their own way and fight for it. I will remember the Canyon Tree Frogs. I will take my own stand.
Forests are now less capable of bouncing back after wildfires
An investigation into the resilience of Rocky Mountain forests has determined that the warming conditions of climate change will make forests less capable of recovering from wildfires.
Researchers led by Colorado State University analyzed data from 1,500 sites in Colorado, Wyoming, Washington, Idaho, and Montana. They measured more than 63,000 seedlings left behind from 52 wildfires in the past three decades.
The team set out to determine how the changing climate has affected post-fire tree regeneration, which is a key indicator of forest resilience.
The results of the study were discouraging. Among other findings, the experts noted significant decreases in tree regeneration following wildfires in the early 21st century, a period which was much hotter and drier than the late 20th century.
“We often talk about climate change and how it will affect us in the future, but the truth is we are already seeing those changes,” said study co-author Camille Stevens-Rumann. “Disturbances like wildfires are a catalyst for change. In many places, forests are not coming back after fires.”
“What we’ve found is dramatic, even in the relatively short 23-year study period,” she added.
In one-third of the sites examined for the study, there were no seedlings growing. These regions were the hottest and driest, where fires were so intense that no trees survived to produce seed.
Forests change over time, but the researchers said that the results of their analysis suggest that it will now take much longer after a wildfire for sites to return to forests, if they return at all.
“Even if we plant trees in those areas, it’s unlikely to be successful,” said Stevens-Rumann. “We need to start expecting that these landscapes aren’t going to look the same in the future, whether it’s reduced density of trees or no longer a forest.”
One of the most shocking aspects of the study was data on the average annual water deficit at study sites.
“In my lifetime, you can see these sites becoming substantially hotter and drier,” she said. “Many forest managers want post-fire years to be cooler and wetter, to help with regeneration, and that’s just not happening anymore, or happening very infrequently.”
Stevens-Rumann said that trees similar to the ones that burned have typically been planted to start the recovery process on a fire-ravaged site, but that may no longer be the best strategy.
“Managers may want to plant species that are adapted to the current and future climate, not the climate of the past,” she said. “There also are areas that could support certain tree species but there isn’t any regeneration currently; these are the ideal places to plant after a fire.”
Water removal from Colorado River putting fish species at risk
The Colorado River Delta used to be a historically low-salinity river system that consisted of the huge Colorado River, which flowed into the Northern Gulf of California. Due to the unique freshwater conditions, ecological species evolved and adapted to the low-salinity environment, and are distinct from closely related species in the saltier estuaries in other regions of the Gulf.
However, due to invasive agriculture and domestic activities consuming much of the Colorado River water, the river is now more similar in salinity to the other estuary systems in the Gulf of California. The nature and severity of the impact of this fresh-water loss on the ecosystem and fisheries of the Colorado Delta and Gulf of California is controversial.
A new study in the journal PeerJ finds that there are risks to the unique local biodiversity of the tidal portion of the Delta that were previously unknown. Researchers from the University of California, Los Angeles (UCLA) analyzed species of silverside fish in a genus that is only found in the Gulf of California.
One species, Colpichthys hubbsi, only lives in the Delta and is on the endangered species list due to its restricted range. Through genetic and morphologic analyses, the researchers revealed that this species hybridizes along the western edge of the Delta with Colpichthys regis, a relative of C. hubbsi that is widespread throughout the estuaries in the Gulf. In earlier museum collections, no evidence of hybridization between these species was found.
While the genes from C. regis – the widespread species – were found to be common in the range of the C. hubbsi – the Delta specific species. However, there were no genes from the C. hubbsi found anywhere else in the Gulf. This shows clear evidence of gene movement in one direction between the two species, which may put the Delta species at risk of extinction as its genome is replaced by genes of C. regis.
But it isn’t just one species that is affected by this change in salinity. Other groups of fishes – as well as crabs – appear to have evolved as ecological species unable to leave the Colorado Delta’s ecosystem. These species may also be at risk.
As water extraction continues to accelerate in large river systems around the world, it is likely that the loss of ecological species in deltas and estuaries around the world is also accelerating. Although more work needs to be done to determine the exact causes of species separation, it’s clear that efforts need to be made to slow down the destruction being done to these ecosystems.
Where does methane in the ocean come from?
Methane is a greenhouse gas the contributes heavily to global warming. It’s a byproduct of many industrial and agricultural activities, as well as a byproduct of the metabolic processes of bacteria. But along with these known sources, there is the unknown phenomenon of methane release from the ocean, which has long puzzled scientists due to the fact that no known methane-producing organisms live near the ocean’s surface.
Several years ago, Wilfred van der Donk, a professor of chemistry at the University of Illinois and one of the paper’s senior authors, discovered a microbial enzyme that produces a compound called methylphosphonate. This molecule can become methane when a phosphate molecule is cleaved from it, and it is found in a microbe that lives near the ocean’s surface.
However, this enzyme was not identified in other ocean microbes, as it was expected to be. Van der Donk and his team searched for other versions of this enzyme by using its genetic sequence (MPnS), but they could never find an exact match in other microbes. What they did find instead was a closely related enzyme, hydrooxyethylphosphonate dioxygenase (HEPD), but this enzyme cannot be cleaved to produce methane.
Seemingly stuck, Van der Donk asked Catherine Drennan, an MIT professor of chemistry and biology and an expert in determining chemical structures of proteins, if she could determine the structure of MPnS. In doing so, it may help the researchers to find more variants of the enzyme in other bacteria. Drennan’s team used X-ray crystallography to find the enzyme’s structure and compared its structure to the HEPD enzyme, finding one small but crucial difference. On the active site of both enzymes, where chemical reactions are catalyzed, there is an amino acid called glutamine. In MPnS, glutamine binds to iron, which is a required cofactor for methylphosphonate production. The glutamine is fixed in an iron-binding orientation by the amino acid isoleucine. But in HEPD, the isoleucine is replaced by glycine, which isn’t as bulky and allows the glutamine more space to rearrange and not have to bind to iron.
“We were looking for differences that would lead to different products, and that was the only difference that we saw,” says David Born, a graduate student at MIT and one of the study’s lead authors. The researchers then determined that changing the glycine in HEPD to isoleucine was enough to allow conversion of the enzyme to MPnS.
Through searching databases of genetic sequences for thousands of microbes, the team found hundreds of enzymes with the same structural configuration seen in the original MPnS enzyme. In addition, all of these were microbes that are known to live in the ocean.
While this discovery could have significant implications, there is still a lot of work that needs to be done. “We know that methylphosphonate cleavage occurs when microbes are starved for phosphorus, but we need to figure out what nutrients are connected to this, and how is that connected to the pH of the ocean, and how is it connected to temperature of the ocean,” says Drennan. “We need all of that information to be able to think about what we’re doing, so we can make intelligent decisions about protecting the oceans.”
Hundreds of turtles killed by entanglement in ocean trash
Hundreds of marine turtles are killed each year from becoming entangled in waste found in oceans and on beaches, including plastic six pack rings that are commonly used for packaging beer and soda cans.
The rise in plastic marine litter is harming turtles of all species, and a recent worldwide survey reports that 91 percent of turtles found entangled in garbage are dead. The research by the University of Exeter also finds that there is a substantially larger impact on hatchlings and young turtles.
The experts detailed serious wounds from entanglement, ranging from choking to maiming. Some of the surviving turtles were forced to drag debris along with them.
Besides plastic six pack rings, turtles are getting caught up in fishing nets, nylon fishing line, plastic packaging, wooden crates, and many other types of waste. The research is part of a growing collection that is exposing the extent of the threat of plastic pollution to marine animals.
Lead author Professor Brendan Godley says that, as plastic pollution increases, more and more turtles are likely to become entangled.
Death from entanglement has already increased substantially with both marine mammals and birds as well.
Of the 106 experts surveyed on the Atlantic, Pacific Caribbean, Mediterranean and Indian ocean coast, 84 percent said that they had found turtles tangled in waste, including plastic debris and discarded fishing gear.
Overall, the investigation showed that more than 1,000 turtles are likely to die annually due to entanglement. The researchers acknowledge, however, that this figure is likely to be a “gross underestimation” of the actual threat to turtles. Not all dead turtles get stranded on beaches and those that are stranded are not always found. For example, some turtles are taken by local people to eat.
“Plastic rubbish in the oceans, including lost or discarded fishing gear which is not biodegradable, is a major threat to marine turtles,” said Professor Godley. “We found, based on beach strandings, that more than 1,000 turtles are dying a year after becoming tangled up, but this is almost certainly a gross underestimate. Young turtles and hatchings are particularly vulnerable to entanglement.”
“Experts we surveyed found that entanglement in plastic and other pollution could pose a long term impact on the survival of some turtle populations and is a greater threat to them than oil spills. We need to cut the level of plastic waste and purse biodegradable alternatives if we are to tackle this grave threat to turtles’ welfare.”
The study is published in the journal Endangered Species Research.
Image Credit: Kate Charles, Ocean Spirits
Satellite data reveals vibrant life on the Antarctic seafloor
An international team of scientists has managed to use an ocean model combined with satellite data to describe and project biodiversity on the floor of the Antarctic Ocean. The unprecedented study was conducted by an incredibly diverse group of researchers, including earth scientists, physicists, geologists, and biologists.
Satellite images of phytoplankton color on the sea surface were used with connected models that represent how the microalgae are swept by ocean currents, sink to the seafloor, and are then redistributed across it. Using this system, the team was able to accurately predict life on the seafloor without the need for physical probing.
Jan Jansen from the University of Tasmania Institute for Marine and Antarctic Studies is the study’s lead author. Jansen explained that the breakthrough would support better conservation and management of biodiversity in the Antarctic.
“For the first time, we are able to predict how much food is available to organisms on the Antarctic sea floor, and therefore how much life is supported across the region,” said Jansen.
“Scientists have long known that there was a relationship between organic matter on the surface and life on the seafloor,” he explained. “But until now there hasn’t been a reliable model that not only explained the link but also enabled predictions of biodiversity.”
Jansen said that the “food availability model” brings together analysis of the rate at which organic matter sinks with data about changing ocean currents on and above the seafloor.
“The model’s predictions about how much food there will be in a particular area have been verified by physical sampling of seafloor sediments,” said Jansen. “This system of models allows broad scale predictions of seafloor biodiversity over vast regions of the Antarctic continental shelf that were previously hidden, as well as predictions about how climate change will affect the ecosystem.”
Jansen said the new system will also help to develop improved strategies for the management and conservation of specific parts the ocean.
Study co-author Professor Craig Johnson explained that while the study was based on a region in eastern Antarctica, the new strategy could be used to produce maps of biodiversity around the entire Antarctic continent, including areas where information is currently limited and challenging to obtain.
“This information would be very valuable and is an exciting prospect,” said Professor Johnson. “With further research, this system of models has the potential to provide valuable insights into seafloor biodiversity across other parts of the world’s oceans.”
The study is published in the journal Nature Ecology & Evolution.
Image Credit: Jonny Stark/Australian Antarctic Division
Buildings must be made more energy efficient to hit climate goals
A recent assessment finds that time is running out for cutting energy use in compliance with the Paris Agreement. The review indicates that the energy intensity per square meter of buildings must improve by 30 percent over the next 12 years to stay on track with the international target.
The Global Status Report 2017, released by the Global Alliance for Buildings and Construction, details how quickly the building sector is growing. 230 billion square meters of additional buildings will be constructed over the next 40 years. This is the equivalent of adding the floor area of Japan to the planet every single year through 2060.
Construction is responsible for 39 percent of energy-related CO2 emissions. Population growth between 2010 and 2016, combined with rising floor area per person and greater demand for energy services, contributed to an increase in new energy demand in buildings equal to all the energy consumed by Germany during the same time frame.
The report cautions that time is running out for staying on target with the limits set forth by the Paris Accord. This warning is primarily because over half of new buildings expected by 2060 will go up in the next 20 years, and two-thirds of them will be constructed in countries that do not have mandatory building energy codes.
The review, however, points out many energy-efficient and low-carbon solutions that can be taken advantage of, which have been successfully deployed across the globe.
“Over the next 40 years, the world is expected to build 230 billion square metres in new construction – adding the equivalent of Paris to the planet every single week,” said Fatih Birol, Executive Director of the International Energy Agency. “This rapid growth is not without consequences.
“While the energy intensity of the buildings sector has improved, this has not been enough to offset rising energy demand. Ambitious action is needed without delay to avoid locking in long-lived, inefficient buildings assets for decades to come.”
A 30 percent improvement in the sector’s energy intensity would require nearly doubling the current rate of energy performance advancements in buildings each year through 2030. This means that buildings with almost zero emissions need to become the worldwide standard within the next decade.
The report points to many examples of buildings that meet this standard, such as the zero-energy Edge building in Amsterdam. This building maximizes solar electricity production and uses smart technologies such as intelligent ventilation systems.
The use of such smart controls could lower the energy consumption of buildings by 10 percent globally, and could save nearly twice the amount of energy used by this sector in 2017
The Global Status Report 2017 is available for download at https://globalabc.org/.
Why meteoroids burn up before they reach Earth
In 2013, a 65 foot-wide meteoroid entered Earth’s atmosphere and hurtled over the city of Chelyabinsk, Russia.
The meteoroid weighed an impressive 10,000 tons as it exploded over Chelyabinsk with a shockwave that injured a little over 1,000 people, shattered windows, and collapsed a factory roof.
The explosion, caught on tape as a streaking fireball across the sky, caused skin and retinal burns, glowing 30 times brighter than the sun.
The Chelyabinsk event is still studied today, and recent research was able to use the major meteor explosion to show how our atmosphere protects against meteoroid impacts.
Researchers from Purdue University discovered that Earth’s atmosphere works as a natural shield, and the force of air pushing against the meteoroid as it enters Earth’s gravitational pull causes it to crack and explode.
The study was published in the journal Meteoritics & Planetary Science.
It’s well established that meteoroids often explode before they reach Earth’s surface, but researchers were unclear as to why this happened until now.
The researchers from Purdue collected data from the Chelyabinsk event to help model how meteors explode in the atmosphere.
The Russian meteor weighed 10,000 tons, but only 2,000 tons of debris were recovered, which means something occurred in the atmosphere to cause the meteoroid to break up into smaller pieces.
The researchers used a computer code that made allowances for both solid mass and air pressure during different meteor trajectories on course with Earth.
The results of the calculations showed that air pressure in front of a meteor was so forceful that air could move through the meteorite and break it apart.
“There’s a big gradient between high-pressure air in front of the meteor and the vacuum of air behind it,” said Jay Melosh, a professor of Earth, Atmospheric and Planetary Sciences at Purdue University and the co-author of the paper. “If the air can move through the passages in the meteorite, it can easily get inside and blow off pieces.”
This study proves that Earth’s atmosphere works as a natural barrier against debris and porous meteors, but the researchers caution that larger, denser objects could very easily reach the surface.
New west coast earthquake warning system could save lives
ShakeAlert is an earthquake early warning system that has been under development for over a decade, and may result in a U.S. West Coast prototype that could see limited public use in 2018. The system uses a dense network of seismic stations that transfer data to a central processing and alert system. The alert information is then distributed to users as an early earthquake warning.
In two papers published in Seismological Research Letters, researchers detail the main components and testing platform for this prototype ShakeAlert system – which is currently being tested in California, Washington, and Oregon.
“Parts of Los Angeles and San Francisco are covered pretty well by regional network stations, but many areas of California, Washington and Oregon are not covered very well,” explains Monica Kohler, a research faculty member at Caltech. “There’s some funding in the works to get some new stations in place, but right now it’s not enough to complete the regional arrays that are necessary for earthquake early warning in its most robust form.”
This system was developed using seismic data collected by the Advanced National Seismic System (ANSS), which is a national collection of seismic networks supported by the U.S. Geological Survey. In total, roughly 760 seismic stations currently contribute to ShakeAlert. However, one of the top priorities for improving ShakeAlert is the addition of almost 1000 additional stations on the West Coast.
At the moment, the ShakeAlert system is testing the use of “volunteer” accelerometers – mainly in the Los Angeles area – which detect earthquakes and can be plugged in at a home or business, eliminating the need for a full-scale seismic station. The system’s algorithms also help determine a “point source” for an earthquake, but it’s still a work in progress. “We are working on the ability to incorporate algorithms that can handle very large earthquakes that happen in a way that can’t be approximated to a single point,” says Kohler. The current system is not as successful at providing useful warnings for earthquakes that rupture a long section of a fault and evolve over time.
Along with providing earthquake warnings and pinpointing the point source, ShakeAlert is also now testing algorithms that provide data on how severe the ground is shaking for users at their exact location. While the system was developed for the West Coast, a similar system could be used for early earthquake warnings in places such as Hawaii, Alaska, or even Oklahoma. “We have been getting questions along the lines of ‘can we try your system where we live?’ or ‘can we port your system over?’” Kohler says. “The answer in theory is yes, but there have to be these certain key elements in place.”
The ShakeAlert team is currently working to get those elements in place, as well as perfect their current system on the West Coast. Improving and expanding this system may one day save the lives of many people in earthquake-heavy areas.