Tuesday, March 12, 2013

The Glaciers of Nepal


                Glaciers form in bowl shaped hollows called Cirques, where more snow falls than gets melted each year. This snow slowly becomes compressed into ice sheets in a process called Firnification. These ice sheets eventually form together, creating glaciers. These glaciers contain nearly 70% of the Earths freshwater, and they are slowly melting, slowly causing problems for those dependent on glacial melt water. The majority of the world’s glaciers are located in the Himalayas, and their melt water feeds several of Asia’s greatest rivers. 

                After a glacier begins to overflow the Cirque is was formed in they start moving down the mountain. Extreme pressures created by meters of ice cause the bottom layers of glacialice.to melt without the temperature increasing to over 32°F. This water melt, combined with the wonderful force of gravity move glaciers downhill, anywhere from a couple of centimeters in a single day to fifty meters in a single day. As glaciers move across the landscape, nothing can stop them. They erode the landscape around them, carving a trail down the mountain. Sediment gets dragged along with them, from soil and clay to large rocks weighing thousands of pounds.
As Glaciers flow, ice crystals move around due to extreme forces and lots of sediment. This sediment is called Glacial Till, its unsorted sediment from the movement of the Glacier. At the end of the glacier, this Till is deposited and the resulting formation is a Glacial moraine.

                These glaciers, while beautiful and powerful are slowly going away. In recent years, due to global warming, these glaciers are melting rapidly. If a glacier disappears, important stored water will disappear, hurting those who rely on this water to survive. Glaciers are great water stores, because people rely on melt water from them, and when they aren’t melting the replaced by a larger amount of fallen snow.  A more immediate danger to people is glacial lakes, which are formed by excessive melting. These lakes are at risk for bursting, creating large floods that can wipe away people and buildings located in surrounding locations.
In 2009, a report by the Nepali Minister for Forest and Soil Conservation warned that more than 20 glacial lakes in Nepal were at risk for bursting. This became a reality last year,when one finally burst. The resulting flood killed 10 people, and another 60 went missing.







Sources:
http://news.xinhuanet.com/english/2009-04/30/content_11287152.htm

http://www.thehindu.com/news/international/10-killed-60-missing-as-glacial-lake-burst-in-nepal/article3387581.ece

http://www.ekantipur.com/2011/08/03/intl-coverage/two-glaciers-in-nepal-to-disappear-research/338486.html

http://education.nationalgeographic.com/education/encyclopedia/glacier/?ar_a=1

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CDoQFjAA&url=http%3A%2F%2Fassets.panda.org%2Fdownloads%2Fhimalayaglaciersreport2005.pdf&ei=Za0_UbHDBMyhyAH15oGoDg&usg=AFQjCNEqPv82Bp2DIDNeN4tb30gD_IewmA&sig2=dWMJMVFS73qiZ-9UBpFlsQ&bvm=bv.43287494,d.aWc

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