Posts Tagged "arctic"

Roundup: Glacier Park, Lahars, and Glacial Ecosystems

Posted by on Mar 6, 2017 in All Posts, Featured Posts, News, Roundup | 0 comments

Roundup: Glacier Park, Lahars, and Glacial Ecosystems

Spread the News:ShareRoundup: Glacier Park, Lahars and Ecosystems Glacier National Park Embraces Sustainability From Xanterra: “Just 150 years ago, 150 glaciers graced these spectacular alpine summits. Only 25 remain large enough today to be considered ‘functional,’ say scientists who expect the park’s glaciers to vanish by 2030, with many disappearing before that. People heeding the advice to visit soon will find a variety of national park lodging and dining spots that are making environmental stewardship part of the park experience.” Read more about it here.     Washington State’s Lahar Preparedness From Journal of Applied Volcanology: “As populations around the world encroach upon the flanks of nearby volcanoes, an increasing number of people find themselves living at risk from volcanic hazards. How these individuals respond to the threats posed by volcanic hazards influences the effectiveness of official hazard mitigation, response, and recovery efforts. Ideally, those who are aware of the hazards and concerned should feel motivated to become better prepared; however, research repeatedly shows that an accurate risk perception often fails to generate adequate preparedness… This study explores the barriers that people in the Skagit Valley of Washington face when deciding whether or not to prepare for lahars as well as the impact of participation in hazard management on household preparedness behaviors.” Read more about Washington’s lahar preparedness here.   How Changing Climate Affects Ecosystems From Environmental Research Letters: “Climate change is undeniably occurring across the globe, with warmer temperatures and climate and weather disruptions in diverse ecosystems (IPCC 2013, 2014). In the Arctic and Subarctic, climate change has proceeded at a particularly breakneck pace (ACIA 2005)… However, climate warming is forecast to be even more extreme in the future. In order to predict the impacts of further global change, experiments have simulated these future conditions by warming the air and/or soil, increasing CO2 levels, altering nutrient fertilization, modifying precipitation, or manipulating snow cover and snowmelt timing (Elmendorf et al 2015, Wu et al 2011, Bobbink et al 2010, Cooper 2014). Changes in biodiversity at high latitudes are expected to have profound impacts on ecosystem functioning, processes, and services (Post et al 2009).” Read more about how changing climate affects ecosystems here. Spread the...

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Glaciers Act as Pollutant Transporters in the Arctic

Posted by on Dec 15, 2016 in All Posts, Featured Posts, Science | 0 comments

Glaciers Act as Pollutant Transporters in the Arctic

Spread the News:ShareWhen people think of the Arctic, they often think of polar bears on melting sea ice, not of an area contaminated by pollutants. However, according to an article by Maria Papale et al. in the Marine Pollution Bulletin, findings of polychlorinated biphenyls (PCBs) in the Arctic demonstrate that ice can be a major transporter of pollutants in this remote region. The research team examined the concentration of PCBs in a fjord called Kongfjorden, located in Svalbard in Arctic Norway (79° N, 12° E), in order to understand how the Arctic is affected by pollutants. Given the impact these chemicals can have on human and animal health, the increase in ice melt due to climate change will have serious consequences for the release of these toxins. PCBs are an important type of persistent organic pollutants (POPs); as such, they have a long lifetime in the environment, although they can be broken down by sunlight or some microorganisms. They are compounds once used heavily in the production of refrigerator coolants, electrical insulators and other items from 1929 until the late 1970s, when they were banned in the United States and elsewhere due to health concerns, particularly their carcinogenic effects. The presence of PCBs in Svalbard in the Arctic Basin indicates some form of long-distance transport because the Arctic is thousands of miles from industrial centers where PCBs are produced. Pollutants like PCBs are transported from regions in the northern mid-latitudes into the Arctic by the prevailing winds and ocean currents. As Papale et al. explain, the PCBs deposited from the atmosphere accumulate on the snow and ice. This deposition has a drastic effect on the region, because PCBs that get trapped in the ice are ultimately released into the environment once the ice melts. For this reason, decades-old PCBs can enter rivers and oceans now, as glaciers melt; they are also emitted when PCB-containing materials wear out through use or when they are burned. In the Arctic, concentrations of PCBs are on average 0.2 ng/m3. Those concentrations have increased since the 1980s, after the banning of PCBs in the United States. Once introduced into the food web, the fate of PCBs depends on which bacteria is present in the environment, since bacteria, such as Actinobacteria and Gammaproteobacteria, possess genetic and biochemical capacities for breaking down PCB pollution. Papale et al. gathered data on the occurrence of cold-adapted, PCB-oxidizing bacteria in seawater and sediment along Kongsfjord, a fjord located on the west coast of Spitsbergen, an island in the Svalbard archipelago. The fjord is fed by two glaciers, Kronebreen and Kongsvegen. The outer fjord is influenced by oceanographic conditions, while the inner fjord is influenced by large tidewater glaciers. Higher concentrations of PCBs were observed in the water right next to the glacier (due to high flows of sediment and sea currents) or next to the open sea (likely due to water circulation inside the fjord). The higher concentrations of PCBs next to the glacier indicate the influence of glacial meltwater containing PCBs. Once the PCBs arrive in Svalbard Archipelago by long-range transport, they build up in the glaciers on Kongfjorden, sometimes by attaching to fine-grained particles, which are then incorporated into the ice. When the ice melts in the summer, the glacier meltwater containing PCBs flows into the fjord and could also freeze into sea ice in the winter. Sea ice transported from other regions also brings POPs to the region. For example, Arctic Ocean sea ice that forms near Siberia can contain pollutant-laden sediments; it is carried to Svalbard by currents, receiving depositions from the atmosphere as it travels. It can also contain heavy metals like lead,...

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Glaciers Serve as Radioactive Storage, Study Finds

Posted by on Aug 17, 2016 in Adaptation, All Posts, Featured Posts, Science | 0 comments

Glaciers Serve as Radioactive Storage, Study Finds

Spread the News:ShareThe icy surfaces of glaciers are punctured with cryoconites – small, cylindrical holes filled with meltwater, with thin films of mineral and organic dust, microorganisms, and other particles at the bottom of the hole. New research conducted by Polish scientists reveals that cryoconites also contain a thin film of extremely radioactive material. The study confirms previous findings of high levels of radioactivity in the Arctic and warns that as Arctic glaciers rapidly melt, the radioactivity stored in them will be released into downstream water sources and ecosystems. The study, headed by Edyta Łokas of the Institute of Nuclear Physics at the Polish Academy of Sciences and researchers from three other Polish universities, was published in Science Direct in June. The study examines Hans Glacier in Spitsbergen, the largest and only permanently populated island of the glacier-covered Svalbard archipelago, off the northern Norwegian coast in the Arctic Ocean. While investigating the radionuclide and heavy metal contents of glacial cryoconites, the researchers revealed that the dust retains heavy amounts of airborne radioactive material and heavy metals on glacial surfaces. This radioactive material comes from both natural and anthropogenic, or human-caused, sources, according to the study. However, the researchers determined through isotope testing that this deposition was mainly linked to human activity. Head researcher Edyta Lokas says she believes that this radioactive material mainly derives from nuclear weapons usage and testing. “The radionuclide ratio signatures point to the global fallout [from nuclear weapon testing], as the main source of radioactive contamination on Svalbard. However, some regional contribution, probably from the Soviet tests performed on Novaya Zemlya was also found,” Lokas wrote in an email to GlacierHub. The Arctic region bears an unfortunate history of radioactive contamination, from an atom bomb going missing at the U.S. base in Thule, Greenland, to radiation from Chernobyl getting picked up by lichens in Scandinavia, making reindeer milk dangerous. But how does all this radioactive materials end up in the Arctic? The Arctic, and polar regions in general, often become contaminated through long-range global transport. In this process, airborne radioactive particles travel through the atmosphere before eventually settling down on a ground surface. While these particles can accumulate in very small, non harmful amounts in soils, vegetation, and animals in all areas of the world, geochemical and atmospheric processes carry the majority of radioactive particles to the Poles. Once the particles reach the Poles, “sticky” organic substances excreted by microorganisms living in cryoconites attract and accumulate high levels of radioactivity and other toxic metals. As cryoconites occupy small, but deep holes, on glacier surfaces, they are often left untouched for decades, Edyta explains. Cryoconites also accumulate radioactive substances that are transported with meltwater flowing down the glacier during  summertime. Climate change lends extra meaning to the study, as the researchers note that, “the number of additional contamination sources may rise in future due to global climate changes.” They expect that both air temperature increases and changes to atmospheric circulation patterns and precipitation intensity will all quicken the pace of contamination transport and extraction from the atmosphere. Edtya explained that as Arctic glaciers retreat, “The radioactivity contained in the cryoconites is released from shrinking glaciers and incorporated into the Arctic ecosystem.” She said she hopes that future climate change vulnerability assessments of the Arctic to pollution consider cryoconite radioactivity. Spread the...

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Ice loss surpasses poaching as largest threat to Barents Sea polar bear

Posted by on Aug 10, 2016 in All Posts, Featured Posts, Science | 0 comments

Ice loss surpasses poaching as largest threat to Barents Sea polar bear

Spread the News:SharePrior to the 1970s, hunting decimated polar bear populations across the Arctic. The international community has made strides in protecting the iconic species from over-harvesting through conservation agreements, which have helped the species start to recover. However, a review paper published in Polar Research in July suggests that the road to recovery is far from over, as ice loss now replaces poaching as the most pressing threat to polar bear survival in the Barents Sea area, north of Norway and Russia. The paper, written by Magnus Anderson and Jon Aars, of the Norwegian Polar Institute, comprehensively covers the history of polar bear population changes over the course of 100 years. By examining historical documents and current scientific studies, the authors find that ice loss, in conjunction with human encroachment on habitat and pollution, have replaced hunting as the largest threat to polar bear populations in the Barents Sea area. Somewhere between 100 and 900 polar bears were poached each year between 1870 to 1970 in Greenland and the Barents Sea region. Arctic countries then came together to protect the species as the bears were pushed toward the brink of extinction. In 1973, the Agreement on the Conservation of Polar Bears was facilitated by the International Union for Conservation of Nature and signed by five countries, marking an important step in the conservation of the polar bear and Arctic ecosystem. With the additional support of Russia’s and Norway’s polar bear hunting bans, enacted in 1956 and 1973, respectively, the Barents Sea polar bear’s outlook became more promising. In Svalbard, a glacier-rich archipelago north of the Norwegian mainland, polar bear populations doubled in the decade following the conservation agreement. There were approximately 2,000 bears in the region as of 1980. While population recovery occurred, it happened slower than anticipated by the scientific community. The Intergovernmental Panel on Climate Change mentioned the impacts of climate change on sea-ice cover for the first time in its third assessment in 2001. The inclusion of ice loss in the report shed light on a potential new threat to polar bear populations, which depend on the Arctic ice for their way of life. It also offered an explanation for the slow recovery of the species following the Russian and Norwegian poaching bans. According to current assessments, the polar bear habitat in the Barents Sea will substantially decrease over the next few decades due to ice loss and glacier retreat, as a consequence of anthropogenic climate change. Polar bear populations are expected to decline accordingly. The Polar Research study states that the main reason for the loss of polar bear populations will be the loss of an ice “platform” needed to hunt for prey — ringed, bearded, and harp seals. As the ice melts, polar bears lose their hunting grounds and must travel greater distances under more treacherous conditions in order to find food. Anderson and Aars cite prior studies conducted by Carla Freitas, Ian Stirling, and others which have tracked trends in polar bear movement with GPS collars and have found that the thickness and persistence of ice significantly affects the location of polar bears and their hunting grounds. In addition to impacting the species’ hunting ability, ice is critical for breeding, traveling, and denning. A loss of  habitat means fewer travel routes for males to find females during the breeding season and a drop in breeding rates across the Arctic. According to the authors’ research, when females have to give birth and raise their cubs, they are hard-pressed to find suitable denning and birthing areas. In the fall, the ice and snow begins...

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“Red snow” algae accelerating glacier melt in the Arctic

Posted by on Jul 13, 2016 in All Posts, Featured Posts, Science | 0 comments

“Red snow” algae accelerating glacier melt in the Arctic

Spread the News:ShareScientists have discovered a troubling new characteristic of the tough algae that grow on the surface of Arctic glaciers: not only do they turn the glacier surfaces red, they accelerate the melting of the ice. Across the Arctic, from Greenland to Sweden, glacier ice is turning red in what has been termed “watermelon snow.” The phenomenon has become increasingly common in recent years, yet little is known about the algae or their broader environmental impacts.   A recent study, published June 22 in Nature Communications, has shed light on the red snow, reporting that the algae are contributing to glacier melting and climate change in the Arctic. The Arctic region covers the majority of the Earth’s northern pole, and contains over 275,500 square kilometers of glaciers. It is also one of the most vulnerable regions to climate change, warming at a rate nearly twice the global average.  According to NASA, the rate of Arctic warming from 1981 to 2001 was a staggering 8 times larger than the rate of melting over the last 100 years. Given the severity of glacier melt in the region, understanding the factors that impact melting rates is crucial to preserving the Arctic ecosystem. Albedo is one of the most important influences on glacier melt, and the presence of red algae is now speeding up the process. Due to their red pigmentation, algal blooms on ice substantially darken the surface of the glaciers and change their albedo—or the amount of light reflected off of the surface of an object. Just as black concrete is much hotter to the touch than a pale sidewalk, glaciers covered in red algae absorb more light and melt at a faster rate than clean white ice. This sets off a chain reaction of additional melting, as the meltwater creates a habitat for algae to colonize, and low-albedo rocks and dirty ice underneath glaciers are exposed. The research team, led by Stefanie Lutz of the University of Leeds, found that the algal blooms are decreasing snow albedo by as much as 13 percent over the course of the melt season in the summer. The phenomenon is widespread. Forty red snow samples were taken between July 2013 and July 2014 from a total of 16 glaciers in Svalbard, Northern Sweden, Greenland, and Iceland. Results were similar across the board in the different regions. Local ecology, geography, and mineralogy did not have an impact on the ability of the algae to bloom—they are cosmopolitan, able to colonize and spread easily across an ecosystem. While the researchers found a rich diversity of bacteria in the glacier samples, the algae did not show the same pattern. Instead, results revealed that the spread of red algae was almost entirely attributable to a small group of algal species–the Chlamydomonadaceae being the most common. Six taxa groups made up over 99 percent of the algae species found in all Arctic locations. These finding set the Arctic apart from other terrestrial ecosystems, which tend to be less homogenous, and indicate that these few species of algae can survive and thrive under a wide range of conditions, and are also likely to spread to other locations. This makes the findings of the study even more pertinent, as red snow will become an increasingly common phenomenon while glacier melt accelerates. According to the study, “Extreme melt events like that in 2012, when 97% of the entire Greenland Ice Sheet was affected by surface melting, are likely to reoccur with increasing frequency in the near future as a consequence of global warming.” Lutz and the research team conclude that there...

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