Beijing (China), Aug 2 (Canadian-Media): Melting Himalayan glaciers are releasing decades of accumulated pollutants into downstream ecosystems, according to a new study, said Mary Caperton Morton, GeoSpace, Phys.org reports said.
The high mountain glaciers of the Tibetan Plateau feed thousands of alpine lakes that form the headwaters of many of Asia’s major rivers. Credit: NASA, Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center
The new research in AGU's Journal of Geophysical Research: Atmospheres finds chemicals used in pesticides that have been accumulating in glaciers and ice sheets around the world since the 1940s are being released as Himalayan glaciers melt as a result of climate change.
These pollutants are winding up in Himalayan lakes, potentially impacting aquatic life and bioaccumulating in fish at levels that may be toxic for human consumption.
The new study shows that even the most remote areas of the planet can be repositories for pollutants and sheds light on how pollutants travel around the globe, according to the study's authors.
The Himalayan glaciers contain even higher levels of atmospheric pollutants than glaciers in other parts of the world "because of their proximity to south Asian countries that are some of the most polluted regions of the world," said Xiaoping Wang, a geochemist at the Chinese Academy of Sciences in Beijing and an author on the new study.
For pollutants, there is no away
Pollutants can travel long distances through the atmosphere on dust particles and water molecules. Previous studies have shown that Arctic and Antarctic ice sheets contain high levels of pollutants that traveled thousands of kilometers before dropping onto ice and being incorporated into glaciers. This phenomenon of high levels of contamination far from sources of pollution, known as the Arctic paradox, is also seen in high mountain glaciers like those in the Himalaya.
The Nam Co Basin, on the central Tibetan Plateau in the Himalaya between the Gangdise-Nyainqȇntanglha mountains to the north and the Nyainqȇntanglha range to the south, is home to more than 300 glaciers that covered nearly 200 square kilometers in 2010. But the ice is melting: Between 1999 and 2015, the total volume of ice in the Nam Co Basin decreased by nearly 20 percent.
Due to global warming, Himalayan glaciers are melting at an unprecedented rate, releasing decades of accumulated pollutants into ecosystems downstream, Wang said. To better understand this cycle, Wang and colleagues measured the concentrations of a class of chemicals used in pesticides called perfluoroalkyl acids (PFAAs) in glacial ice and snow, meltwater runoff, rain and lake water in Nam Co Basin.
By testing ice, snow and water samples collected in the Nam Co Basin, Wang and colleagues found glaciers in the region are releasing around 1,342 milligrams of PFAAs per day into Lake Nam Co. They detected levels as high as 2,171 picograms per liter in the lake. Under these conditions, the estimated total annual input of PFAAs into Lake Nam Co is approximately 1.81 kilograms per year.
"In general, the results are comparable to previous studies on lakes in polar regions," the team wrote.
That kind of influx of PFAAs can have an impact on aquatic life in the lake and downstream, said Kimberley Miner, a geochemist and climate scientist at the University of Maine in Orono who was not involved in the new study.
PFAAs are known for having a very long lifespan. The chemicals don't regularly biodegrade and are readily passed through organisms and ecosystems, while being continually concentrated through various biogeochemical processes, Miner said. The new study did not include a toxicity risk assessment of these levels on aquatic life, but previous studies suggest that eating fish caught in the lake could be detrimental to human health, she says.
"The bioaccumulation potential for these chemicals is extraordinary," Miner said.
First, microorganisms and insects take up molecules into their tissues, then fish and other predators eat them, passing the contaminants up the food web in higher and higher concentrations.
"This [Nam Co Basin] water also feeds directly into the water resources in India," she added.
The study adds important data to the bigger picture of how pollutants cycle around the globe, Miner said. Similar studies have been conducted at the poles and in Europe, but not as much is known about pollutants in the Himalaya. Each mountain range has its own characteristics that influence how chemicals move through the environment, she added.
"The Earth is a closed system. Everything released on the Earth, stays somewhere on the Earth," Miner said.
#EarthOvershootDay; #regenerationOfEarthEcosystem; #GlobalFootprintNetwork
Ottawa, July 29 (Canadian-Media) Earth Overshoot Day (EOD) is being observed today all over the world, media reports said.
World Overshoot Day (above)/Facebook Earth Overshoot day (below)/Facebook
EOD marks the date when humanity’s demand for ecological resources and services in a given year exceeds what Earth can regenerate in that year.
This year the world is observing the EOD much earlier, three months earlier than 20 years ago.
Earth Overshoot Day is hosted and calculated by Global Footprint Network (GFN), an international research organization that provides decision-makers with a menu of tools to help the human economy operate within Earth’s ecological limits and promotes real-world solutions that that accelerate the transition to one-planet prosperity
The concept of Earth Overshoot Day was first conceived by Andrew Simms of the UK think tank New Economics Foundation, which partnered with Global Footprint Network in 2006 to launch the first global Earth Overshoot Day campaign. At that time, Earth Overshoot Day fell in October. World Wide Fund (WWF), the world’s largest conservation organization, has participated in Earth Overshoot Day since 2007.
Earth Overshoot Day is not just one special day of the year. It is an effort to celebrate biocapacity, our planet’s biological power to regenerate life. This primary productivity of nature is the source for all life, including human life.
With rising relevance of biocapacity and how we manage determines humanity’s future as we face the daunting challenges of climate change and resource constraints.
Understanding biocapacity’s relevance enables us to better understand how to design cities and economies with significantly higher chances of long-term success. This, and more, is explained in Ecological Footprint: Managing Our Biocapacity Budget.
This book demonstrates how ecological overshoot is shaping the 21st century and shows that the only path forward, for humanity’s sake, is to run our economies on nature’s regeneration, not on natural capital liquidation.
And we emphasize that it can be done. The key tool for the job is Footprint and biocapacity accounting, applied to countries, cities and companies.
(Reporting by Asha Bajaj)
Penn State (U.S.), July 28 (Canadian-Media): A volcano will not send out an official invitation when it's ready to erupt, but a team of researchers suggest that scientists who listen and watch carefully may be able to pick up signs that an eruption is about to happen, physics.org news reports said.
In a study of Hawaii's Kīlauea volcano, the researchers reported that pressure changes
in the volcano's summit reservoirs helped explain the number of earthquakes—or seismicity—in the upper East Rift Zone. This zone is a highly active region where several eruptions have occurred over the last few decades, including a spectacular one in 2018.
"We are interested in looking at the mechanisms that trigger seismicity at a very active and dynamic volcano, like Kīlauea Volcano in Hawaii," said Christelle Wauthier, assistant professor of geosciences and Institute for CyberScience co-hire, Penn State. "There are several physical processes that can drive seismicity and, in this study, we were trying to find out which one was the most likely."
Pressure changes in the summit reservoirs of Kīlauea may help explain the number of earthquakes — or seismicity — in the volcano’s upper East Rift Zone. Credit: USGS
According to Wauthier, the pressure changes that occur in the summit reservoir—an underground chamber hosting hot magma—causes stresses in the rocks and ground that surround the magma, even not at its immediate proximity. These stress changes can trigger small magnitude volcano-tectonic earthquakes, most of the time imperceptible to humans but that are picked up by the sensitive seismic equipment that monitor the volcano. This seismic activity, then, may better predict magma movements and resulting eruptions.
The researcher's work challenges a previous theory that suggested the seismic activity in the rift zone was being triggered by the volcano's gradual slip toward the sea. The southern flank of Kīlauea is gradually moving toward the ocean at about six centimeters a year.
While most people picture volcanoes violently erupting at their summits, Kīlauea is different because its sprawling system of underground tunnels and chambers where magma flows results in eruptions that can happen at various points miles from its summit. When magma travels out of these chambers and onto the Earth's surface, it is called lava.
"Underneath, there is a conduit system that is extremely long—we're talking 20 miles or so," said Wauthier. "And it's just like the plumbing in a house. A volcano's plumbing system can be plugged up or blocked and that just might lead to an eruption."
By better understanding the forces that are triggering seismicity, scientists monitoring seismic activity at other volcanoes could predict future eruptions more accurately, according to the researchers, who reported their findings in a recent issue of Geology. Because Kīlauea is one of the world's most closely and densely monitored volcanic systems, it serves as a living laboratory to study volcanic activity that can be applied to study other volcanoes, added Wauthier, who worked with Diana C. Roman, staff scientist, Carnegie Institution for Science, and Michael P. Poland, scientist-in-charge, Yellowstone Volcano Laboratory, U.S. Geological Survey.
"While there are only a few volcanoes that are as highly instrumented as Kīlauea, which has a super-dense seismic network and GPS, so it's very well-monitored, but other volcanoes are not monitored like that," said Wauthier. "However, for volcanoes that have good seismic networks—and there are many of them—you can apply the exact same approach as this one to look if your volcano-tectonic seismicity—these small earthquakes—are due to magma being injected into a magma reservoir, or due to something else."
The team used both seismic and satellite imagery data from mid- to late-2007 for the study. Seismic analysis was conducted with data collected on the upper East Rift Zone from the U.S. Geological Survey Hawaiian Volcano Observatory (HVO). Using information from global positioning satellites, also collected by HVO, the researchers were also able to analyze physical changes to the mountain's shape and paying particular attention to ground surface deformations at the summit. They then looked at how these factors correlated with models of the stress changes caused by inflations and deflations of the summit reservoir.
By carefully analyzing movements to a volcano's summit reservoir, researchers may be able to better predict when and where eruptions are likely to occur, then, according to the researchers. However, more work needs to be done, said Wauthier. Future research plans include looking at seismic activity and ground deformation data from other time periods of the volcano.
"We've been looking at the period in 2007, but that's just a subset," said Wauthier. "We could imagine just looking at a longer time period where we have other inflation-deflation events happening and see if we still conclude that same thing that it's magma reservoir inflating that triggers the seismicity. It is likely that over the course of a long-term eruption like the 1983-2008 one, things are changing."
Bringham, July 26 (Canadian-Media): Fun fact: The microscopic worms Brigham Young University (BYU) professor Byron Adams studies are not only the most abundant animal species on earth, they also make up four-fifths of animal life on this planet. That's right, four out of every five animals on earth are nematode worms, Science X Newsletter reports said.
BYU biology professor Byron Adams travels annually to Antarctica and the Arctic north to carry out research. Credit: BYU
A new study of soil nematodes co-authored by Adams reveals that there are 57 billion of them for every single living human being—much greater than previously estimated. They also have a total biomass of about 300 million tons, approximately 80 percent of the combined weight of Earth's human population.
The study, co-authored by Adams and published Wednesday in Nature, provides conclusive evidence that the majority of these tiny animals live somewhere experts did not expect: high latitude arctic and sub-arctic soils (i.e. tundra, boreal and temperate forests, and grasslands).
"Until recently, life beneath our feet has pretty much been terra incognita" says Adams. "Since we didn't know much about life in the soil, most scientists just assumed that patterns of abundance below ground would match what we see above ground. We figured the tropics must be where it's at. Turns out, that's not true at all. The reason this paper is kind of a big deal is that we show just the opposite is true."
Knowing where these tiny worms live matters because nematodes play a critical role in the cycling of carbon and nutrients and heavily influence CO2 emissions. An important finding of the paper is that nematode abundance is strongly correlated with soil carbon (more carbon = more worms). Understanding the little organisms at a global level is critical if humans are going to understand and address climate change.
Microscopic soil nematodes in action. Credit: Brigham Young University
For the study, researchers took 6,759 soil samples representing every continent, and every environment, from arctic tundra to tropical rainforest. They used microscopes to analyze the density of each type of nematode and generate a representative global dataset. Using the information, they built models which predict nematode populations for each square kilometer and create the first global high-resolution maps of soil nematode density.
For the past 17 years Adams, has traveled annually to the ice-free areas of Antarctica to study nematodes, tardigrades (water bears) and other microscopic creatures. His research program studies the roles these animals play in fundamental ecosystem processes as well as how they survive in extremely cold and dry environments.