June 23, 2009
Scientists Begin Further Studies On Himalayan Glacial Lakes
Researchers in Nepal are conducting the first ever field studies of Himalayan glacial lakes, which seem to be rising due to climate change, BBC News reported.
The team conducted its first field visit in May at a lake in the Everest region, and later in the year will undergo similar surveys of two other glacial lakes in the central and western part of the Nepalese Himalayas.Arun Bhakta Shrestha, a climate change specialist with the International Center for Integrated Mountain Development (ICIMOD), which is carrying out the research alongside a number of government agencies, said the team started with Nepal, but plans to extend studies to other Hindu Kush Himalayan countries.
He said they were conducting regional assessments of the floods that these lakes can cause if they overflow.
The scientists are now reviewing the data they collected on the Imja lake, yet they say it will take some time before they release their final conclusions.
Researcher Pradeep Mool, a remote sensing specialist with the ICIMOD, said there was an air of change in and around Lake Imja, but the changes aren't alarming.
"The area of the lake has become bigger and there are some changes in its end moraines [accumulations of debris]," he said.
However, mountaineers in the area have been more vocal about the changes they've noticed. Some sherpa climbers have noted fast glacial retreat and snow meltdown in the Himalayas.
Last month, after returning from his 19th climb to the highest peak, Appa Sherpa said recently that he had seen fresh water at the height of above 26,000 feet on Everest.
"I was shocked to see fresh water at that altitude, where I had seen nothing but snow and ice before," he said.
Appa served as a "climate witness" for green group WWF's campaign to raise awareness of the impact of climate change on the Himalayas.
The Himalayas have earned the name "white spot," because of the almost 20 year gap in field studies and data-gathering in the region. The majority of the studies have been desk-based, with the help of satellite imagery and computer simulations.
Nearly 10 years ago, the UN Environment Program (UNEP) and ICIMOD warned that 20 glacial lakes in Nepal and 24 in Bhutan were swelling so rapidly that they could burst by 2009.
Buildings and roads or even whole communities in countries like Nepal and Bhutan could be swept away by flash floods should a lake burst, and this has already happened more than 30 times in and around Nepal in the last 70 years.
A hydropower station, a trekking trail and numerous bridges were washed away in 1985 after a glacial lake burst in Khumbu in the Everest region.
Nearly 2,300 of the 3,300 glaciers in the Nepalese Himalayas contain glacial lakes and no one knows which lakes are nearing breaching point.
However, field studies on the Imja, Thulagi and Tsho Rolpa glacial lakes should begin to give scientists an idea.
Locals panicked over the rising waters of the Tsho Rolpa until some water was drained from it almost ten years ago.
Funding difficulties have caused a lack of field studies over the potential danger of these lakes, but things appear to be turning around.
Shrestha said they have attempted to go beyond desk-based assessments, which were largely hazard focused, and they are also considering more on risk as opposed to hazard, meaning they are looking at physical, economic and social aspects.
But it's also about bringing specialists from different fields together, said Mool.
He said they are trying to link science, policy making and public awareness through the studies' findings, so that what they find becomes practically useful for the society.
These field studies could also indicate how rivers in the regions might change, as major local rivers, like the Ganges, Bramhaputra, Meghna and Indus, have most of their tributaries fed by snow melt from Himalayan glaciers.
These rivers are likely to swell significantly and cause frequent flooding as glaciers melt rapidly due to global warming, according to previous studies and computer simulations.
Scientists say that in the long term, when the glaciers have retreated, the rivers could dry up almost entirely during the dry season"”causing an unprecedented crisis in the water supply for millions of people in the region.
Now researchers have the means to begin determining when and how likely such events might happen.
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