Posts by Yixing Zhu

Pre-industrial Anthropocene Detected in Peru

Posted by on Mar 31, 2015 in All Posts, Art/Culture, Featured Posts, Images | 0 comments

Pre-industrial Anthropocene Detected in Peru

Spread the News:ShareHumans may have begun to pollute the atmosphere earlier than we thought. So says recent research conducted at the Quelccaya Ice Cap in Peru, where scientists drilled into the ice to pull out cores, which they could read like ancient texts. Those cores show widespread traces of copper and lead starting in about A.D. 1540, which corresponds to the end of the Inca empire and a period of mining and metallurgy when the areas that are now Peru and Bolivia became part of the Spanish Empire. The findings, published by Paolo Gabrielli and colleagues in February in the Proceedings of the National Academy of Sciences, suggest for the first time that the Anthropocene, the geological epoch defined by massive and widespread human impacts on the planet, began about 240 years before the industrial age arrived on the scene with its steam engines and its coal plants. Scientists have long used glacier ice cores to learn about the Earth’s climates and air pollution and reconstruct pollution histories. In Greenland, for example, they have traced metals found in ice cores back to ancient Greek and Roman mining operations. The pattern of climate changes and air quality are recorded in the ice itself as glaciers grow, accumulating layer after layer of ice, year after year. For example, winter layers are often thicker and lighter in color, while summer layers are often thinner and darker because of less snowfall and more dust in summer. Scientists can read these layers much in the same way they read tree rings to calculate historical environmental conditions, including snowfall and atmospheric composition. Once the scientists have removed the ice cores from a glacier, they can analyze the trace elements in the ice itself. They also study the air bubbles trapped in those cores at the time of their formation to learn about the chemical components of the atmosphere. According to Paolo Gabrielli, an Earth scientist at Ohio State University, anything in the air at the time the glacier layer was formed, such as soot particles, dust and a wide variety of chemicals, will be trapped in the ice layers as well. Gabrielli says there are no glaciers on Earth in which traces of anthropogenic air pollution cannot be detected. Gabrielli and his team found that lead levels in the Quelccaya ice core doubled between 1450 and 1900, while the amount of chemical element antimony (Sb) in the ice was 3.5 times greater than  before. They also compared data from a peat bog in Tierra del Fuego, Chile, and from sedimentary lake records from regions including Potosí and other mines throughout Bolivia and Peru to determine the path the pollution took, and found that most of the pollution was carried to the Quelccaya Ice Cap in Peru by the wind. In the 16th century, the Spanish colonial authorities forced the indigenous populations in South America to extract ore and refine silver from the mountaintop mines of Potosi. They introduced mercury amalgamation, a new technology, to expand silver production, which lead to dramatic increases in the amounts of trace metals released into the atmosphere. “This evidence supports the idea that human impact on the environment was widespread even before the industrial revolution,” Gabrielli said in a statement on Ohio State University’s website. While the industrial economies in 20th century produced more pollution than any other time in human history, colonial mining should be considered the beginning of the Anthropocene, according to these new findings. For more information about Quelccaya, look here. Spread the...

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New Route Up Mt. Everest

Posted by on Mar 11, 2015 in Adaptation, All Posts, Featured Posts, Images, News, Tourism | 1 comment

New Route Up Mt. Everest

Spread the News:ShareLast year’s deadly avalanche on Mt. Everest in Nepal, which killed 16 Sherpas–mountaineering guides indigenous to the region–has led to new safety recommendations for both guides and tourists. The Nepalese authorities have ordered climbers to shift their path up the mountain, to avoid the route of last year’s disaster, according to Vice magazine. The new path will bring people to the middle of the Khumbu Icefall, instead of the west shoulder of the Icefall, where the guides were buried in the avalanche. The new path might be more technically difficult for climbers, but government officials say it is safer. Last year, the Nepalese government came under fire for failing to sufficiently compensate Sherpa families for the guides’  deaths and for attempting to keep climbing season open, putting the lives of guides and climbers at risk. Tourism is the largest industry in Nepal, providing 4% of gross domestic product, and the tourists come for Mount Everest, the highest mountain peak in the world. Of the nearly 800,000 tourists who visited Nepal in 2013, over 10% went hiking or climbing. Though the number of guides killed last year is high, the record for highest number of total deaths from a single accident occurred in 2001, when a blizzard and several avalanches in central Nepal are reported to have killed at least three local guides and 26 tourists, including Israelis, Poles, Nepalese, Canadians, Slovaks and one person from India. Recent data suggests that avalanches are the primary cause of death among guides in the Nepalese Himalayas, while falls are the primary cause of death among visitors. (See Figure 1 to the left.) Some 102 guide deaths were caused by avalanches between 1950 and 2006 of a total of 211 guide deaths, while 223 tourist deaths were caused by falls from high elevations, followed by 170 tourist deaths by avalanches over the period. A steady decrease in deaths among both tourists and guides began in about 1975 and lasted until 2005, at which point the trend reversed itself. The Kang Guru avalanche and three separate avalanches on Ama Dablam, Ganesh VII, and Pumori in 2006 killed 14 tourists and 18 guides and marked the beginning of an upswing. Figure 2, below, shows the trend in death rates from 1950 to 2006 among both tourists (“members,” in blue) and guides (“hired,” in red). As climate change melts glaciers around the world, avalanches could increase, threatening tourists and guides with more accidents. Even for the local Sherpa guides, the Himalayas become unfamiliar territory when the landscape is changed by receding ice. “Warmer temperatures and water from melting ice can combine to weaken a glacier’s grip on the underlying rock,” Jeffrey Kargel, a University of Arizona geologist, who has conducted regular studies on glaciers near Everest, told Vice magazine. To read more about last year’s Everest accident and the aftermath, read this post. Spread the...

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Tracking Glaciers From Space: GLIMS

Posted by on Feb 11, 2015 in All Posts, Featured Posts, Images, Science | 0 comments

Tracking Glaciers From Space: GLIMS

Spread the News:ShareIn 1994, an international group of scientists came together to form GLIMS (Global Land Ice Measurements from Space), a worldwide initiative to monitor and study glaciers using satellite data. For at least one hundred years, scientists had primarily used traditional field measurements to track glacier dynamics, but field data are by necessity limited in scope, and can be expensive and laborious to obtain. The GLIMS team ultimately chose to use an imaging system called Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), jointly managed by NASA and Japan, for their glacier measurements. ASTER is installed aboard Terra, the flagship satellite of NASA’s Earth Observing System (EOS), which was launched in December 1999. ASTER data can be used to map land surface temperature, reflectance, and elevation, which allows the scientists to distinguish between glacier ice and snow and to measure changes in glacier volume. Using digital images and data provided by ASTER, GLIMS created an up-to-the-minute database of the world’s glaciers, which includes ID, name, cross-references, and analysis of the state and dynamics of individual glaciers. In August 2014, GLIMS published their findings in book form: Global Land Ice Measurements from Space compiles these glacier profiles, provides a review of analysis methodologies for measuring changes in glacier volume, and offers predictions for future glacier change as well as some interpretations of potential impacts for policymakers in the context of climate change. The GLIMS scientists provide firm evidence that glaciers are shrinking worldwide, and they believe the cause is global warming. The GLIMS book offers a basic theoretical background in glacier monitoring and mapping as well as remote sensing techniques. It also discusses measurements of glacier thinning from digital elevation models (DEMs), and calculation of surface flow velocities from satellite images. DEMs can provide specific data for every pixel in a satellite image, with a margin of error at 0.5m/year. Although cloud cover can interfere with accurate satellite data on glaciers, scientists are able to identify and discard this faulty data. As described in the book, GLIMS scientists Siri Jodha Singh Khalsa and his colleagues have been able to assess the mass balance of alpine mountain glaciers by comparing historical topographic maps and DEMs derived from ASTER. For instance, they built a model and limited the error in the computation of mass balance from field measurements of China’s Sarytor glacier to less than 150mm/year. Similarly, using techniques established by Dr. Todd Albert,who is also a member of GLIMS, a set of images of the Quelccaya Ice Cap spanning four decades was analyzed to create a history of ice surface area. Overall, Albert found that the ice cap has retreated from 58.9 km2 in 1975 to 40.8 km2 in 2010, with a loss of surface area of 31%. This history matches what has been observed in the field by glaciologists Lonnie Thompson and Henry Brecher since the 1970s. Thanks to GLIMS, the rate of glacier melting can be measured and documented more precisely, providing readers with potential evidence of climate change. The GLIMS data provides solid support for future scientific research and planning in the face of climate change. For other stories on the measurement of glaciers, look here. Spread the...

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Roundup: NZ photos, vanishing ice art, murder mystery

Posted by on Feb 9, 2015 in All Posts, Art/Culture, Featured Posts, Images, News, Roundup | 0 comments

Roundup: NZ photos, vanishing ice art, murder mystery

Spread the News:ShareGlacier melting recorded by photos “A series of photographs taken over 10 years has revealed the dramatic changes to one of New Zealand’s most famous glacier.The Massey University scientists who took the pictures – at the same time each year during surveys – say the changes to Fox Glacier on the South Island’s West Coast are also having a major impact on the surrounding landscape, with the valley rising by more than a metre in the last two years.” Read more about these photos here. Vanishing Ice Exhibition across Canada “The exhibit shows climate change in a new way, says Barbara Matilsky, the curator behindVanishing Ice. “Many people are aware of the critical importance of ice for the planet,” she says, adding that she wanted to focus on how the artistic legacy of ice has helped shape Western views of the natural world. The exhibition — which contains over seventy works by fifty artists from twelve countries — begins a three-month run on Saturday at the McMichael Canadian Art Collection in Kleinburg, Ontario (before this, it visited Calgary’s Glenbow Museum.) Because it covers a span of over two centuries, the exhibition provides some unique opportunities to see changes, both in the icy landscapes themselves and society’s view of them.” Read more about this exhibition here. New murder mystery ““Fortitude,” an ambitious 12-episode murder mystery beginning on last Thursday night, takes place in two unusual locales. One is its slightly fantastical far-far-north setting, a fictional Arctic island — based on the Norwegian archipelago of Svalbard — where a small international community is outnumbered by polar bears; crime is thought to be nonexistent; and anyone near death is exiled to the mainland, because bodies can’t be buried in the permafrost.” Read more about this here. Spread the...

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New Glacial Lakes to Transform Swiss Landscape

Posted by on Jan 27, 2015 in Adaptation, All Posts, Featured Posts, News, Policy and Economics | 0 comments

New Glacial Lakes to Transform Swiss Landscape

Spread the News:Share In 1983 this lake was a glacier (Monday, Switzerland) #climatechange @Sportscene_tv pic.twitter.com/vls2CY9bST — Nick H. (@nickhdg) September 28, 2013 Ongoing climate change is causing glaciers in the Swiss Alps to shrink dramatically, and some predict they will disappear entirely by the end of the century. As they melt over the coming decades, Swiss scientists estimate that 500 to 600 new lakes covering close to 50 square kilometers of land will form in Switzerland. That’s about the equivalent of two Lake Eries, the eleventh largest lake in the world. “The rapid melting of glaciers is radically changing the Alpine landscape,” world renowned Swiss glacier expert and University of Zurich professor Wilfried Haeberli reported at the annual meeting of the European Geosciences Union (EGU) in Vienna, according to Spiegel. flooding in Lucerne, switzerland (Source: Flickr/Nick Edelen) Haeberli and a team of scientists recently completed a project that attempts to predict where and when these new lakes will form using glacier bed models and time-based ablation scenarios for all Swiss glaciers. Using case studies, they also looked at the potential natural hazards that could be created by these new lakes, the development potential they might offer in terms of hydroelectric energy and tourism and legal issues they might present in terms of ownership, liability, exploitation and conservation. One lake in particular they studied was Lake Trift in the Valley of Gadmen, which appeared in the 1990s due to melting of the Altesch Glacier. Local authorities built a breathtaking suspension bridge over the lake that has since become a tourist attraction. Energy companies are also considering putting it to use for the generation of hydroelectric power. The creation of a dam, which would be necessary for such a project, would likely diminish the attractiveness of the site for tourists, but it could protect the area against the risk of flooding. suspension bridge at Trift lake (Source: Flickr/Bossl) “Whether the lake remains natural or becomes artificial, there is a significant risk of rock or ice avalanches due to the longterm destabilisation of slopes previously supported by the Trift glacier and the potential collapse of the current glacier tongue,” the scientists write. “Such avalanches can trigger a surge wave in the lake with disastrous consequences. The construction of a dam of adequate size could protect the area from floods and allow for the generation of power but it would reduce the appeal for tourists.” Haeberli and his colleagues urge that debates over some of these complex issues begin now, before the Swiss landscape transforms from one of glaciers to one of glacial lakes. Spread the...

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