melting-glacier

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In the middle of the Alaskan Gulf a distinct difference in colour between two adjacent bodies of water has been noticed. The explanation would be that the fresh water of a melting glacier and the the saline water from the ocean have different densities and did not mix immediately.

Read more on these pictures by Ken Smith here

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Leave it to  Pope Francis, a  Jesuit trained as a chemist, who has only one lung, to breath new life into a tired global environmental debate.

It has been droning on for so long now that it has become background noise, easily drowned out in the din of the 24-hour news cycle. While the glaciers melt, and close to 2,500 people in India are killed by a heat wave that produced a 118 degree ambient air temperature, we’d much rather dissect the twists and turns of “Game of Thrones” in our air conditioned parallel universe. The brutality of a make-believe place is so much easier to cope with than confronting the cruelty that defines so much of our own real world.

The head of the Catholic Church might just have inaugurated a vital conversation about how we define prosperity

nytimes.com
Climate Model Suggests Everest Glaciers Could Nearly Disappear
A new computer model suggests that without changes to greenhouse gas emissions, the Everest region of Nepal could lose 99 percent of its glaciers by the end of the century.
By Rachel Nuwer

By the end of this century, the landscape around Mount Everest may drastically change. As the planet continues to warm, the Everest region of Nepal could lose most of its glaciers, according to a study published in the journal The Cryosphere.

“We did not expect to see glaciers reduced at such a large scale,” said Joseph Shea, a glacier hydrologist at the International Center for Integrated Mountain Development in Nepal and lead author of the new report. “The numbers are quite frightening.”

Dr. Shea and his colleagues found that moderate reductions in greenhouse gas emissions could result in a 70 percent loss of glaciers around Mount Everest, while a business-as-usual scenario in which emissions remain at the same levels could result in a 99 percent loss.

To arrive at these findings, Dr. Shea and his colleagues used a computer model for glacier melt, accumulation and redistribution. They customized the model with data on temperature and precipitation, measurements from the field and remote-sensing observations collected over 50 years from the Dudh Koshi basin, which includes Mount Everest and several of the world’s other highest peaks.

The model took into account how much mass glaciers gain from snowfall, as well as the way that mass is redistributed by continual downward movement. The researchers applied the model to eight future climate scenarios, from moderate emissions reductions to none at all.

The results do not bode well for the glaciers around Everest. Even if emissions are reduced by midcentury and rain in the region increases, the model predicts that the majority of the glaciers will probably disappear by 2100.

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Ice caves under Mendenhall glacier, Juneau, Alaska, USA.
Mendenhall, the famously 12 mile long, 150 foot deep and half mile wide glacier melts as you watch it, and moves as much as 60-70 feet per year. The Ice Caves are inside the glacier, accessible only to those willing to kayak to, and then ice climb over the glacier. However, the glacier is retreating increasingly fast as global warming heats the oceans and temperatures rise.

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From NASA Earth Observatory Image Of The Day; July 3, 2015:

Obersulzbach Glacier Plus Four

It might sound counterintuitive that less ice can lead to more glaciers, but that has been the case in Austria’s Obersulzbach Valley. As the Obersulzbach Glacier system has retreated, ice tributaries that were once connected to the main glacier have become stranded—earning them their own identity.

Sensors aboard Landsat satellites acquired this pair of false-color images showing the disaggregation of the glacier system. The Thematic Mapper on the Landsat 5 satellite captured the top image on August 6, 1988; theOperational Land Imager (OLI) on Landsat 8 captured the second image on September 4, 2013. Both images use a combination of visible, near-infrared, and shortwave infrared light. Snow and ice appear turquoise; liquid water is dark blue; and exposed land and vegetation is brown and green. Use the image comparison tool to see how ice loss has divided Obersulzbach into five separate glaciers.

Obsersulzbach Glacier flows along a valley within the Central Eastern Alps, in the Hohe Tauern mountain range. In the 1980s, Obsersulzbach was Austria’s third-largest glacier. But even then, the retreat was well underway, as evidenced by a 1930s Austrian military map (re-published in a blog post by Mauri Pelto).

Landsat satellites have afforded a more frequent view of the glacier’s change. The 1988 image (top) shows the glacier when it stretched 1.4 kilometers farther up the valley from its position in the 1934 map. In 1988, Bleidacher Glacier had already detached from Obersulzbach’s main trunk.

In 1998, researchers found that a lake had formed at the glacier’s receding snout. By 2013 (second image), melt water had swelled the lake to 450 meters long and 200 meters wide. Also by this time, all four “new” glacier segments had separated.

During the 25 years between the two images, Venediger Glacier changed the most, retreating 1.6 kilometers. Sulzbacher lost 1.4 kilometers, Bleidacher lost 1.3 kilometers, Krimmerlertorl lost 0.8 kilometers, and Obersulzbach lost 0.6 kilometers.

The pattern of shrinking glaciers in Obersulzbach Valley corresponds with the behavior of other glaciers in the region. Research published in 2011 estimated that glaciers across the Alps would lose about 75 percent of their volume by the end of the 21st century.

References and Further Reading

NASA Earth Observatory images by Jesse Allen, using Landsat data from the U.S. Geological Survey. Caption by Kathryn Hansen. Instrument(s): Landsat 4 - TM; Landsat 8 - OLI