Posts by Anna LoPresti

Ocean temperatures main cause of glacier melt in the Antarctic Peninsula

Posted by on Aug 4, 2016 in All Posts, Featured Posts, Science | 0 comments

Ocean temperatures main cause of glacier melt in the Antarctic Peninsula

Spread the News:ShareAlong the 1,200 kilometer western coastline of the Antarctic Peninsula, hundreds of glaciers stretch down to the sea. Glacier melt from this region is a major contributor to global sea-level rise. While scientists have looked to rising atmospheric temperatures to explain the rapid glacier melting in recent decades, a new study reveals that ocean temperatures may actually be the main cause of glacier retreat in the region. The Antarctic Peninsula is in the northernmost part of the continent, and lies 1,000 kilometers from the tip of South America. Due to its latitude between 63 and 70 degrees South, the peninsula has the most moderate climate and — relatively speaking — warmest temperatures in Antarctica. As a result, glacier retreat in this area occurs at a faster rate than in most of the rest of the continent. However, melting has accelerated in recent years, raising concern in the scientific community. The atmospheric temperature record over the past several decades shows warming in the region. Rising atmospheric temperatures have, until now, been considered the largest contributing factor to glacier melting on the peninsula. This study, published in Science on July 15, offers a new explanation in its surprising finding that ocean temperatures correlate more closely to glacier melt than air temperatures. The team, led by Alison Cook of Swansea University in the United Kingdom, investigated the relationship between ocean temperatures and glacier retreat in response to research, which showed that the air temperature record in the Antarctic Peninsula did not correctly predict the timing or location of glacier melt in the region. Along the Antarctic Peninsula, there has been more ice loss in the colder southern end of the peninsula than in the warmer north. Air temperatures fail to explain this dramatic gradient along the peninsula, leading the team to seek another explanation. Using detailed data from the World Ocean Database, the researchers were able to track ocean temperatures along the Antarctic Peninsula between 1945 and 2009. When this data was compared to observed glacier retreat over time, a strong connection was revealed. In the southern portion of the Antarctic Peninsula, mid-depth ocean temperatures were higher than in the north. By dividing the ocean near the peninsula into 6 study regions, the team of researchers from Swanea and British Antarctic Survey found that the ocean water composition was very different between the top and bottom half of the peninsula. Along the southwestern coast of the peninsula, water from multiple oceans meets to form Circumpolar Deep Water (CDW). In this region, a mix of Antarctic, Pacific, and Atlantic water masses dominates the ocean composition. The temperature and salinity of the water along the southwestern coast is unique because of the mixing of different water sources — cold salty water sinks, while warmer water settles at mid-range depths. The CDW in the region has an average temperature of 4 degrees Celsius above the seawater freezing point. However, Shelf Water and Bransfield Strait Water surround the northern portion of the peninsula. These waters are only 1 and 2 degrees above seawater freezing point, respectively. The warmer southern waters correspond to the areas of the peninsula that have had the most glacier melt, and explain why the southern peninsula has more ice loss than the northern area. While it may seem that the surface temperature of the water would be the most important factor affecting glacier melt, the team found that it is actually the temperature of water 100 to 300 meters below the surface that correlates strongest with glacier melt — the bottom of the glaciers extending off the coastline fall within this range,...

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Survival is just the tip of the iceberg in Blair Braverman’s memoir on Arctic life

Posted by on Jul 28, 2016 in All Posts, Art/Culture, Experiences, Featured Posts | 0 comments

Survival is just the tip of the iceberg in Blair Braverman’s memoir on Arctic life

Spread the News:Share“On a bad day we called it the Goddamn Ice Cube. On a good day Summer Camp on the Moon.”   In her memoir published July 5, writer and musher Blair Braverman recounts her time living in the isolated wilderness of the Arctic, and her struggles to reconcile the many contradictions—both real and perceived—that accompanied her journey. Over the course of its 274 pages, Welcome to the Goddamn Ice Cube: Chasing Fear and Finding Home in the Great White North provides an honest and eloquent narrative of Braverman’s personal pursuit to create a home in the fjords of Norway and glaciers of Southeastern Alaska. While Braverman’s experiences in the north were not always positive, she persistently returns to the Arctic to overcome her fears and self-doubts–seeking safety in extreme environments and confronting her status as an outsider in a “man’s world.” Her Arctic roots trace back to a young age. Braverman spent a year in Oslo when she was 10-years-old and continuously returned, feeling connected to the country in a way that she never felt in her hometown of Davis, California. A year as a high school foreign exchange student in Norway helped her reestablish her connection. But a host father who made her feel unsafe also made her time there difficult. Braverman was insecure, but not defeated. As testament to her personal strength and character, she pushed herself to return to Norway and struggle through the extreme physical and mental challenges of survival training and dog sledding in the Arctic at the Norwegian Folk School 69°North. “I knew I would never be a tough girl,” she writes in the memoir. “And yet the phrase, with its implied contradiction, articulated everything that I wanted for myself: to be a girl, an inherently vulnerable position, and yet unafraid.” In the far reaches of the North, there were many things to fear—the biting cold, the seemingly unending darkness of winter, being buried alive under the snow. However, Braverman approached these physical challenges head-on throughout her time at 69°North and in the years to follow. “Of course I was scared. But at least I was scared of dangers of my own choosing. At least there was joy that came with it.” There were other equally pressing physical and emotional dangers that Braverman faced, one of which is not exclusive to the Arctic: the danger of men threatening her safety and encroaching on her body. In the eyes of the men Braverman encountered, the Arctic was seen as exclusively male territory. Despite the intimidation, harassment, and dismissal by men, Braverman was determined to have an equal right to also call the Arctic “home.” After completing her survival training at the folk school, Braverman left Norway to work at a summer tour company on a glacier in southeast Alaska. Living on a remote glacier with an aggressive boyfriend, the irony of her job cannot be lost—providing a comfortable experience for tourists to be “explorers” out in the wilderness, when the reality of living in such an environment is anything but comfortable. She writes in the book that she was also “discouraged from acknowledging climate change, even as the glacier melted away beneath us.” While the majority of people may prefer to sweep difficult truths under the rug, Braverman is admirable for her desire to seek it out, regardless of convenience. While Welcome to the Goddamn Ice Cube is, to a large degree, a story of emotional and physical struggle, it is also one of deep admiration for nature and the Arctic. Braverman’s love of the environment is contagious and brought to life through her vivid...

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Photo Friday: Tibetan Plateau From Space

Posted by on Jul 15, 2016 in All Posts, Featured Posts, Images | 0 comments

Photo Friday: Tibetan Plateau From Space

Spread the News:Share55 million years ago, a major collision took place between two of the large blocks that form the Earth’s crust. The Indian Plate pushed into the Eurasian Plate, creating what is known as the Tibetan Plateau. The region, also known as the “Third Pole,” spans a million square miles and contains the largest amount of glacier ice outside of the poles. A photograph of the southern Tibetan Plateau taken from space was released June 17th, showing the dramatic topography in false color. The photograph, taken by the Sentinel-2A, was captured near Nepal and Sikkim, a northern state of India, on February 1st. According to the European Space Agency (ESA), “From their vantage point 800 km high, satellites can monitor changes in glacier mass, melting and other effects that climate change has on our planet.” This week, enjoy stunning satellite pictures of the Tibetan Plateau over time. NASA also has taken photographs of the same plate collision from space, showing the snow-capped Himalayas, which are still rising. A true-color image of the Tibetan Plateau, taken in 2003 by NASA’S MODIS Rapid Response Team, shows the region’s lakes as dark patches against the sand-colored mountains. Prior to the true-color photograph, a spaceborne radar image of the Himalayan Mountains was taken in 1994 in southeast Tibet. Each color is assigned to a different radar frequency that depends of the direction that the radar was transmitted. Spread the...

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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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Roundup: Glacier Tourism, Monitoring, and Melt

Posted by on Jul 11, 2016 in All Posts, Featured Posts, Roundup | 0 comments

Roundup: Glacier Tourism, Monitoring, and Melt

Spread the News:ShareEach weekly Roundup, we highlight three stories from the forefront of glacier news.   Tourists’ take “last chance” to see New Zealand Glaciers From The International Journal of Tourism Space, Place and Environment: “For more than 100 years, the Fox and Franz Josef Glaciers in Westland Tai Poutini National Park have attracted thousands of tourists annually and have emerged as iconic destinations in New Zealand. However, in recent years, the recession of both glaciers has been increasingly rapid and the impacts on, and implications for, visitor experiences in these settings remain relatively unexplored…Results revealed the fundamental importance of viewing the glaciers as a significant travel motive of visitors, suggesting that there is a ‘last chance’ dimension to their experience. Furthermore, the results demonstrate a high adaptive capacity of local tourism operators under rapidly changing environmental conditions.” To read the full study, click here.   Glacier monitoring in the pre-internet era From AGU Blogosphere: “We have been monitoring the annual mass balance of Easton Glacier on Mount Baker, a stratovolcano in the North Cascade Range, Washington since 1990.  This is one of nine glaciers we are continuing to monitor, seven of which have a 32 year long record. The initial exploration done in the pre-internet days required visiting libraries to look at topographic maps and buying a guide book to trails for the area.  This was followed by actual letters, not much email then, to climbers who had explored the glacier in the past, for old photographs.  Armed with photographs and maps we then determined where to locate base camp and how to access the glacier.” For more, go to the AGU Blog post here, and check out “Easton Glacier Monitoring” by Mauri Pelto on Vimeo   Water scarcity in central Asia From The World Bank: “Communities in Central Asia talk about how water is vital but scarce resource across the region. The Central Asia Energy-Water Development Program (CAEWDP) works to ensure effective energy and water management, including at the regional level. This work should accelerate investment, promote economic growth and stable livelihoods.” http://glacierhub.org/wp-content/uploads/2016/07/The_Water-Energy_Challenge_in_Central_Asia.mp4 For more, click here.  Spread the...

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