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Global Warming Increases Threat of Himalayas' Killer Lakes

Yeshi Dorje

   When a "Himalayan tsunami" roars down from the rooftop of the world,
   water from an overflowing glacial lake obeys gravity. Obliterating
   everything in its path, a burst is predictable only in its
   destructiveness.
   "There was no meaning in it," one person who withstood the waters in
   India's Himalayas [1]told a Public Radio International reporter. "It
   didn't give anyone a chance to survive."
   ChristianHuggel, a professor at the University of Zurich in Switzerland
   who specializes in glaciology andgeomorphodynamics(the study of
   changing forms of geologic surfaces), said thousands of cubic meters of
   water moving down a mountain "is really quite destructive and it can
   happen suddenly."
   That water comes from glacial lake outburst floods, or GLOFs, which are
   increasing in frequency as climate change increases the rate of glacial
   melting. This catastrophic lake drainage occurs wherever there are
   glaciers in places such as Peru and Alaska.
   The most devastating GLOFs occur in the [2]Himalayan regionsof India,
   Pakistan, Afghanistan, Bangladesh, Bhutan, India, Myanmar, Nepal and
   the Tibetan Plateau. When combined, the area has the third-largest
   accumulation of snow and ice after Antarctica and the Arctic.
   Melting glaciers
   In the Himalayas, climate change melted glaciers by a vertical foot and
   half of ice each year from 2000 to 2016, according to a [3]study
   released in June'sScience Advancesby Columbia University's
   Lamont-Doherty Earth Observatory in Palisades, N.Y.
   That is twice the rate of melting from 1975 to 2000.
   Local people have noticed the change. In a 2016 interview from the
   Everest basecamp, Dr. Nima Namgyal Sherpa told VOA that in the past,
   the glacial streams in the mid-Everest region started flowing in May,
   but the Sherpas now see the flow beginning in April.
   That melted snowpack seeps down to fill mountainside indentations to
   form glacial lakes. As global warming accelerates the melting, the
   lakes are expanding, as is their number and threat, monitored in some
   areas with automated sensors and manual early warning systems by army
   and police personnel with communication gear.
   "Bigger lakes may increase the risk of catastrophic dam failure,"
   Joseph Shea, a glacier hydrologist at the University of Saskatchewan in
   Saskatoon, Canada, told the magazine[4]Science.

References

   1. ttps://www.pri.org/stories/2013-11-18/himalayan-tsunami-climate-change-triggers-deadly-floods-among-world-s-highest
   2. https://eos.org/articles/satellite-data-archives-reveal-unrecorded-himalayan-floods
   3. https://advances.sciencemag.org/content/5/6/eaav7266
   4. https://www.sciencemag.org/news/2017/02/melting-glaciers-around-mount-everest-may-be-forming-killer-lakes

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