Posts Tagged "arctic"

“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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Satellites Detect Both Steady and Accelerated Ice Loss

Posted by on May 24, 2016 in All Posts, Featured Posts, Science | 0 comments

Satellites Detect Both Steady and Accelerated Ice Loss

Spread the News:ShareA new study published in Geophysical Research Letters reports the findings of a pair of satellites that measure gravity to get a clearer picture of the continued ice mass loss in Greenland, the Gulf of Alaska, and the Canadian Arctic Archipelago. The study found accelerated ice loss in the Arctic, and steady loss in Alaska, which will have significant implications for sea level rise globally. The researchers, Christopher Harig and Frederik J. Simmons, both of Princeton University, analyzed data from the two satellites, called the Gravity Recovery and Climate Experiment (GRACE), in order to not only find the current state of ice mass within glaciers and ice sheets, but the changes in mass since 2003. GRACE’s dual satellites circle the Earth together, and minute fluctuations in their orbit serve as a basis for measuring the Earth’s gravitational field. The two are separated by approximately 137 miles, and as they fluctuate with the changing gravitational pull, the distance between the two varies slightly. (The two satellites are nicknamed Tom and Jerry, a reference to the cartoon cat and mouse.) Coupling the differing distances with precise GPS locations, GRACE is able to provide a view of the Earth’s gravity with “unprecedented accuracy” as NASA says. This level of detail allows researchers to easily find even minute trends in mass changes. GRACE is more commonly used over large areas, such as ice sheets, but in this research the authors studied areas “near the [lower] limit that can be resolved by GRACE data.” After thermal expansion, mountain glaciers and ice caps are the second highest contributor to sea level rise, making accurate and efficient study of the mass loss from smaller areas critical for future sea level projections. The researchers found that the glacial ice on the north region of the Gulf of Alaska was decreasing at a faster rate than the south region. GRACE detected an unexpectedly large ice loss in 2009 which the authors attribute to a lowered albedo after the eruption of Mount Redoubt. The Canadian Archipelago as a whole has been losing ice mass steadily. Within it, the Ellesmere Island region was stable in 2003, when the data was first collected, but mass loss has been accelerating since. In 2013, the researchers found that the mass loss within the Ellesmere Island region had dramatically accelerated, but has since continued closer to average. Baffin Island, the second area studied within the Archipelago, also saw significant ice loss but not at the same rate as Ellesmere. Greenland saw “an order of a magnitude” more total volume ice loss than Baffin and Ellesmere. Partially due to its sheer size, ice loss there is significant; in the previous decade the largest land-based contributor to sea level rise has been Greenland. As ice mass loss continues in these regions due to natural variability and climate change, it will be important to have accurate and localized data to better prepare for the corresponding sea level rise.   “Worldwide, on the order of 500 million people could be directly impacted by rising sea level by the end of this century. The human impact is combined with a large financial impact as well. So regardless of where people live, I think the impacts of ice loss and sea level rise will be easily seen in the future,” co-author Christopher Harig said in an email to GlacierHub. Spread the...

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PhotoFriday: Kali Moves Into New Home

Posted by on Jun 12, 2015 in All Posts, Featured Posts, Images, News | 0 comments

PhotoFriday: Kali Moves Into New Home

Spread the News:ShareMcDonnell Polar Bear Point of the Saint Louis Zoo welcomed its first occupant – Kali on May 5, 2015. Kali is a two and half year-old, 850-pound orphaned male polar bear. He was turned over to US Fish and Wildlife Service (USFWS) after his mother was killed by an Alaska Native hunter. His new home is located adjacent to Penguin and Puffin Coast at the Zoo, where a large dive pool is bounded by expansive split view windows. “This wonderful habitat shows our commitment to protecting polar bears, which are declining in the wild and are highly vulnerable,” said Jeffrey P. Bonner, Ph.D., Dana Brown President and Chief Executive Officer of the Saint Louis Zoo during interview with the Intelligencer. “By working to not only conserve polar bears in the wild but to offer a wonderful habitat for breeding and caring for bears, we can help save these iconic animals.” Let’s take a peak at how Kali explores his new home at Saint Louis Zoo. As you know, sea ice is crucial to polar bears in terms of survival. Polar bears take advantages of ice floes and breath holes when hunting seals or fish. Dramatic sea ice reductions resulted from increasing temperature has lead to rapid decline in polar bear population. Moreover, polar bears also make use of icebergs which are formed from calving glaciers. The Inuit, indigenous inhabitants of the Arctic, recognize this association between polar bears and icebergs. Aiming to reduce its carbon footprint, the Saint Louis Zoo has carried out sustainable practices. In addition, it tries to promote sustainable behaviors among visitors. Here are some photographs of polar bears. Source: Richard Roche/Flickr Source: TomD./Flickr Source: rubyblossom./Flickr Source: Valerie/Flickr Source: Valerie/Flickr For more information about the Saint Louis Zoo and Kali, visit here.   Spread the...

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Roundup: Cyanobacteria, Glacier Calving and Glacier Fluctuations

Posted by on May 25, 2015 in All Posts, Featured Posts, Images, News, Roundup, Science | 0 comments

Roundup: Cyanobacteria, Glacier Calving and Glacier Fluctuations

Spread the News:ShareArctic biocrust cyanobacterial communities “In the polar regions cyanobacteria are an important element of plant communities and represent the dominant group of primary producers. They commonly form thick highly diverse biological soil crusts that provide microhabitats for other organisms. Cyanobacteria are also producers of toxic secondary metabolites. The north-west coast of Spitsbergen, are able to synthesize toxins, especially microcystins and anatoxin-a. To the best of our knowledge, this is the first report on the presence of ANTX-a in the entire polar region. The occurrence of cyanotoxins can exert a long-term impact on organisms co-existing in biocrust communities and can have far-reaching consequences for the entire polar ecosystem.” See more about this article here   Dynamics of Glacier Calving “During summer 2013 we installed a network of nineteen GPS nodes at the ungrounded margin of Helheim Glacier in south-east Greenland together with three cameras to study iceberg calving mechanisms… The glacier calved by a process of buoyancy-force-induced crevassing in which the ice downglacier of flexion zones rotates upwards because it is out of buoyant equilibrium. Calving then occurs back to the flexion zone… “ See more about this article here.   Reconstruction of glacier fluctuations “It is presented the results of study of bottom sediments of the proglacial lakes enriched with meltwater of Peretolchin Glacier, Chersky Glacier and glaciers of the Kodar Ridge. Bottom sediments were investigated with time resolution in year-season, using X-ray fluorescence. We have defined three periods in significant increase of glacier flow/melting during the last 210 years. The first period (ca. 1800–1890), supply of suspended material by meltwater into Lake Ekhoy and Lake Preobrazhenskoe, was not intense until 1850 and 1875, respectively. However, the rate of meltwater supply into Lake Izumrudnoe was high during the Little Ice Age, and it is likely attributed to local moisture from Lake Baikal. The regional glacier water balances were most likely positive during the second period (ca. 1890–1940). The third period (ca. 1940–till present) was characterised by moderate melting rate of glaciers located on the Kodar and Baikalsky Ridges, in contrast to Peretolchin Glacier that demonstrated the highest rate of melting and changes in outlines during this period.” See more about this article here Spread the...

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Photo Friday: Seals taking it easy on icebergs

Posted by on Jan 16, 2015 in All Posts, Featured Posts, Images | 0 comments

Photo Friday: Seals taking it easy on icebergs

Spread the News:ShareSeals are some of the cutest animals found in the Arctic and the Antarctic. This week’s photo friday features seals carrying out their daily activities on icebergs, which are important environmental features in their chilly habitats. The photos include leopard seals and crabeater seals among other species. Photo Friday highlights photo essays and collections from areas with glaciers. If you have photos you’d like to share, let us know in the comments, by Twitter @glacierhub or email us at glacierhub@gmail.com.   seal family taking a nap big white seal on iceberg (photo: flickr) Crabeater Seals in Pléneau Bay, Antartica leopard seal (Photo: flickr) seal on ice Spread the...

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