Posts Tagged "antarctica"

Iceberg Killing Fields Threaten Carbon Cycling

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

Iceberg Killing Fields Threaten Carbon Cycling

Spread the News:ShareThe vast, unpopulated landscape of Ryder Bay, West Antarctica gives the impression of complete isolation. However, despite its barren, cold exterior, Antarctica plays an important role in regulating the Earth’s climate system. Located along the southeast coast of Adelaide Island, Ryder Bay is helping mitigate impacts of climate change by removing greenhouse gases from the atmosphere to the ocean, where these gases can remain for centuries. This repurposing is being done by benthos, microorganisms like phytoplankton that bloom during summer months and provide critical food supplies that maintain the marine ecosystem in Ryder Bay. Quietly residing on the floor of the Southern Ocean, benthos are encountering increased risks due to a changing climate. While the potential carbon recycling capacity of local marine ecosystems remains significant, the collapsing glaciers and ice shelves in Ryder Bay may threaten this productivity, according to an article in the journal of Global Change Biology. The carbon recycling process in the marine ecosystems is one of the strongest mechanisms helping to reduce the impacts associated with historic carbon emissions. Located along the continental shelf, benthos absorb carbon through photosynthesis; when these organisms die and fall to the ocean floor, this carbon is then stored in sediments. Undisturbed, the ocean can help thwart warming due to an enhanced greenhouse effect by removing carbon from the atmosphere and storing it in the ocean. David Barnes, a Marine Benthic Ecologist with the British Antarctic Survey and an author of the article,  pointed out to GlacierHub, “Trends in carbon accumulation and immobilization, which occur on the seabed, could be considered most important as these involve long-term carbon storage. [These trends] are perhaps the largest negative feedback on climate change.” However, because of shifting land dynamics, the increased frequency of iceberg creation is having a direct impact on the ability of the marine ecosystems to recycle carbon. As the Earth continues to warm, ice sheets and glaciers in Antarctica advance and become thinner, causing cracks and crevasses to form. These fissures, in turn, lead to unpredictable, large-scale breaks which create icebergs that discharge into the ocean. At the time of detachment, ice formations hit the ocean floor, obliterating the marine ecosystems below. Icebergs can continue to impact the benthos as they travel on the ocean. Barnes described this problem to GlacierHub:  “At places like Ryder Bay, it would be very difficult to provide forecasting, because it is very frequent and a bit chaotic. The direction an iceberg travels depends on its shape, how deep its keel is, wind, and current speed. A smaller iceberg with a vertically flat side above water will easily catch wind like a sail, so if the wind is strong it will mainly follow wind direction. Conversely, a bigger iceberg with a deep vertical flat side might more easily catch current.” According to NOAA, these icebergs— typically rising 5 meters above the sea surface and covering 500 square meters in area— are large enough to inflict significant destruction. Dubbed “iceberg killing fields,” these places of impact can cause extensive disruption to the beneficial marine ecosystems along the ocean floor. David Barnes works with the British Antarctic Survey to study the iceberg killing fields and measure the impact of iceberg-seabed collisions on marine ecosystems. The British Antarctic Survey has been monitoring the local marine ecosystems in Ryder Bay due to their sensitivity to environmental change and the surprisingly large role benthos play in removing carbon from the atmosphere. According to the report, “The scour monitoring has probably become the longest continuously running direct measurement of disturbance on the seabed anywhere in the world.” With roughly 93 percent of carbon...

Read More

Small Particles Have Big Impact on Glacial Health

Posted by on Nov 16, 2016 in All Posts, Featured Posts, News, Science | 0 comments

Small Particles Have Big Impact on Glacial Health

Spread the News:ShareA recent study by Heidi Smith et al. in the desolate McMurdo Dry Valleys of Antarctica has shown that microbial life in biofilms is present across a large part of the region’s ice, suggesting that the stability of polar ice can be influenced by even the smallest of organisms. Biofilms—thin, slimy bacterial layers that can adhere to a surface—were discovered in conjunction with the windblown dust that accumulates on snow and ice called cryoconite. The research found that a combination of biofilms and cryoconite is capable of enhancing the rate of glacial melting, meaning that the planet may be more vulnerable to sea level rise than previously imagined. As an important component in the planet’s hydrological and carbon cycles, glacial melting affects sea levels and the chemistry of our oceans. This meltwater enhances the movement of fluids from terrestrial environments to oceans, as well as the transport of nutrients to aquatic ecosystems. In the McMurdo Dry Valleys, the activity of microorganisms on the glacier surface enables the accumulation of organic matter on minerals found in the ice’s dusty cryoconite layers. This relationship results in the darkening of ice over time, making it less efficient at reflecting incoming sunlight than it would be normally. As most of Antarctica’s ice lies atop the continental landmass,  increased melting at the Earth’s southern pole may lead to an appreciable rise in global sea levels. Prior research in alpine glacial environments and on the Greenland Ice Sheet (Langford et al. 2010) established a correlation between biofilm development and the darkening of cryoconite particles, pointing towards the synergistic possibility of biologically enhanced rates of melting. Until the recent publication of key research by Heidi Smith et al., the role of biofilms in Antarctica was largely unknown. In conversation with GlacierHub, Smith stated that “the role of biofilms in different glacial locations has not been explored.” She added “due to differences in environmental pressures (temperature extremes, nutrient availability, levels of UV radiation, and rates of flushing), it is possible that the role of biofilms in glacial surface processes varies by location.” Smith’s team was able to establish the precedence of biofilms at extreme southern latitudes in their research and also contributed to the larger body of scientific evidence supporting the role of microbes in influencing reflectivity, otherwise known as albedo, of glaciers. Smith and her research colleagues employed a variety of methods to investigate the interactions between the biological and mineralogical components of Antarctic ice. Microbial species were identified in the lab via pyrosequencing (which determines the order of nucleotides in DNA by detecting the release of the pyrophosphate ion) as well as epifluorescent microscopy (which utilizes a compound microscope equipped with a high-intensity light source). The team’s research yielded four unique bacterial components in biofilms found in cryoconite holes. Interestingly, Smith told GlacierHub that “while some organisms identified in this study have also been found in cryoconite holes from the Greenland Ice sheet, the relative abundance of individual organisms in each of these locations appears to be geographically distinct.” The primary region for fieldwork and sampling for the study was an ice-lidded cryoconite hole on the Canada Glacier, located near Victoria Land, Antarctica. When asked about why the team chose to work in this isolated region, Smith replied: “There are previous studies from this region that have focused on cryoconite hole geochemistry, rates of microbial activity and microbial assemblage composition; therefore, we could place samples from this study into a larger framework.” Following fieldwork on the glacier, subsequent laboratory analysis showed that enriched levels of nitrogen and carbon isotopes were present when Bacteroidetes...

Read More

Creating the World’s First Ice Core Bank in Antarctica

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

Creating the World’s First Ice Core Bank in Antarctica

Spread the News:ShareGlaciers contain valuable information about past environments on Earth within the layers of ice that accumulate over hundreds or thousands of years. However, alpine glaciers have lost 50 percent of their mass since 1850, and projections suggest that glaciers below 3500m will not exist by 2100. Concerns about the loss of this valuable resource motivated Jérôme Chappellaz, a senior scientist at France’s National Center for Scientific Research (CNRS), and an international team of glaciologists, to create the world’s first archive of ice cores from different parts of the world. Ice cores are cylindrical sections of ice sheets or glaciers collected by vertical drilling. Chemical components within different layers of ice in glaciers, such as gases, heavy metals, chemical isotopes (forms of the same element with different numbers of neutrons in their nuclei) and acids, allow scientists to study past atmospheric composition and to draw inferences on environmental variables such as temperature changes and sea levels. Cores will be extracted between now and 2020, after which they will be transported for storage to Concordia Station in Antarctica, a joint French-Italian base located on the Antarctic Plateau. Antarctica serves as a natural freezer, allowing the cores to be stored 10 meters below the surface at temperatures of -54°C. International management of the archive, which will be large enough to contain cores from up to 20 glaciers, will be facilitated by the lack of territorial disputes in Antarctica. The first cores that will go into the archive were collected in summer 2016 between August 16th and 27th. Over this time period, two teams of French, Italian and Russian researchers successfully collected three ice cores, each 130 meters long and 92 millimeters in diameter, from France’s Col du Dôme glacier (4300m above sea level) on Mont Blanc, the highest mountain in the Alps. Drilling was carried out within drilling tents at nighttime because daytime temperatures were too high. The cores were then cut into one meter sections for storage and transportation purposes. “The cores are currently stored in our commercial freezers at Grenoble, France, waiting for the long term storage cave at Concordia Station in Antarctica to be built,” Chappellaz told GlacierHub. “One of the three cores will be used during the coming two years to produce reference records of all tracers (chemical components of ice that reveal information about the natural environment) that can be measured with today’s technologies.” The next drilling for the archive will take place in May 2017 at Illimani glacier in the Bolivian Andes (6300m above sea level). As with the drilling at Col du Dôme glacier, the project will be overseen by Patrick Ginot, a research engineer at the Laboratory of Glaciology and Environmental Geophysics (LGGE) in Grenoble. The collection of ice cores has relied on intense international collaboration, and Ginot will be working with glaciologists from Bolivia to extract the cores. Illimani is one of the few Latin American glaciers that contains information stretching back to the last glacial maximum around 20,000 years ago. Although ice cores collected from the Arctic and Antarctica, such as those from Dome C, provide information stretching back to that period, the value of the cores lies in the information they are able to provide about specific regions. For example, ice cores from France’s Col du Dôme glacier can provide information about European industrial emissions, while ice cores from Bolivia’s Illimani glacier could offer insight into the history of biomass burning in the Amazon basin. Glaciers will be selected based on a number of criteria, with priority given to glaciers that contain large amounts of information about the regions from...

Read More

Prominent Scientist Gordon Hamilton Dies in Antarctica

Posted by on Nov 9, 2016 in All Posts, Featured Posts, News | 0 comments

Prominent Scientist Gordon Hamilton Dies in Antarctica

Spread the News:ShareGordon Hamilton, a respected glaciologist, died recently while on field research in Antarctica after his snowmobile fell 100 feet into a crevasse. The 50-year-old associate research professor worked at the University of Maine where he studied the effects of climate change on the shrinking glaciers of Greenland and Antarctica. Dr. Hamilton had been conducting field research about 25 miles south of McMurdo Station, the largest of three U.S. research stations in Antarctica, located on the southern tip of Ross Island. He was driving his snowmobile in a remote area known as the McMurdo shear zone where two large ice shelves meet and crevasses are typically found. Leigh Stearns, Assistant Professor at the University of Kansas, who worked with Gordon Hamilton for over 17 years, including for 24 months of fieldwork, talked to GlacierHub about the risks facing researchers like Hamilton: “There are certainly dangers associated with doing fieldwork in remote places,” she said. “However, we spend so much time and effort thinking about these risks and trying to mitigate against them, that I think we’re often safer in the field than at home.” According to Stearns, Gordon was experienced and extremely cautious doing fieldwork. “This trip to Antarctica was no exception. It should be noted that there is nothing anyone could have done to prevent the accident that killed him.” Jonathan Kingslake, a glaciologist at Columbia University, agreed: “I am keen to point out that the risks are not that great and accidents are actually quite rare.” According to Kingslake, many observations vital for understanding ice sheets can only be made by moving around on the surface of the ice, even despite advances in satellite and airborne remote sensing. “Ground-based polar fieldwork involves different risks than you face in normal life,” he said. “For example, extreme cold, light aircraft use, and crevassing. These can be exacerbated by remoteness, but usually the risks can be mitigated successfully. Only rarely do serious accidents happen.” Dr. Hamilton set fear aside in Greenland and Antarctica frequently, including during a decades-long stretch when he went to Greenland two to three times a year for field work. He supplemented his research by using satellite remote sensing to track the shrinking of the ice sheets in both Greenland and Antarctica.  According to an interview Hamilton gave last year, “No research had previously been conducted on the oceanic waters of a typical fjord” in Greenland. By going out into the field, despite known dangers, Dr. Hamilton discovered that water temperatures reached 4°C between 200 meters and 1000 meters below the surface, within 20 km of the edge of the ice sheet. Hamilton believed this was the best explanation for the abrupt changes observed in Greenland over the past 15 years. “They’ve all been caused by the ocean,” he said at the time. Although he knew the risks, as all glaciologists do, Hamilton lived his life with courage, in pursuit of a greater truth about our changing climate. The death of Hamilton in Antarctica has since sent shock waves through the research community. On behalf of the National Science Foundation’s Division of Polar Programs, Dr. Kelly K. Falkner released a statement about the community’s tragic loss. The statement reads: “The U.S. Antarctic Program is a close-knit corps of researchers and support personnel who carry out the nation’s program of research in Antarctica, working at the frontiers of human knowledge, but also at the physical frontiers of human experience. The death of one of our colleagues is a tragic reminder of the risks we all face—no matter how hard we work at mitigating those risks—in field research.” Dr....

Read More

Photo Friday: The Glaciers of Antarctica

Posted by on Oct 21, 2016 in All Posts, Featured Posts, Images, Uncategorized | 0 comments

Photo Friday: The Glaciers of Antarctica

Spread the News:ShareAntarctica, the world’s southernmost continent, is a hostile realm of ice and snow, fictionalized in our popular culture by the likes of H.P. Lovecraft and further romanticized by real-world scientific explorers eager to lay claim to the region. Humans who venture to the southernmost pole do so by way of the Antarctic Peninsula, where they may visit Port Lockroy, site of a former British research station, or take in by cruise the vast terrain and wildlife of the region. Multiple countries also operate scientific camps and research programs in more remote locales of Antarctica where science teams study awe-inspiring glaciers and ice sheets throughout the year. The largest ice sheet in the world, Antarctica is composed of around 98% continental ice and 2% barren rock. The ancient ice is incredibly thick, although it has been thinning due to the effects of climate change. Several nations have made overlapping claims to the Antarctic continent. The Antarctic Treaty, signed in Washington in 1959, attempts to maintain peace, by neither denying or providing recognition to these territorial claims. Today, a total of 53 countries have signed the treaty, including Argentina, Australia, Chile, France, New Zealand, Norway and the United Kingdom, countries that have all made specific claims in the region. The United States and Russia, meanwhile, have maintained a “basis of claim” in the region. Scientists of these nations conduct field research from Antarctica bases to gather greater knowledge about climatic changes affecting the larger world. Studying glaciers in Antarctica is of great impact due to the influence of melting glaciers on global sea levels. In addition, Antarctica plays a primary role in the world’s climate. According to Antarcticglaciers.org, “Cold water is formed in Antarctica. Because freshwater ice at the surface freezes onto icebergs, this water is not only cold, it is salty. This cold, dense, salty water sinks to the sea floor, and drives the global ocean currents, being replaced with warmer surface waters from the equatorial regions.” Ice sheets in Antarctica are fragile and a number have recently collapsed, causing glacial thinning and threatening a rise in sea levels. Some scientists are concerned that the collapsing ice sheets may not be just a natural occurrence but one more closely linked to a warming planet. The Pine Island Glacier is one of the “fastest receding glaciers in the Antarctic” and a major contributor to our rising sea levels, according to the U.S. Antarctic Program. Scientists have observed an ice shelf on the Pine Island Glacier that is rapidly thinning, pushing the glacier toward the sea. A team of scientists constructed a field camp in 2012-2013 to study the impacts of climate change on the glacier, also known as PIG. The PIG field camp staff learned to contend with adverse weather conditions in the area and events like windstorms, a common occurrence in this remote and hostile part of the world. Helicopters provide support to field projects such as the one conducted in 2012-2013 at the Pine Island Glacier. Elsewhere in Antarctica is the McMurdo Dry Valleys, the largest ice-free area in the region—approximately 15,000-square-kilometers— where science teams perform research projects on glaciers, lakes, and soils, funded by the National Science Foundation. The area is an extreme landscape, but it can also be a useful environment for scientists hoping to study the impacts of climate change. In Antarctica, teams of scientists can extract old ice flowing from the ends of glaciers in large quantities rather than by drilling directly into the ancient ice sheet. Around 350 kilograms of ice is then melted into a vacuum-sealed container to capture around 35...

Read More