ISLAMABAD: Owing to climate change, the probability of permafrost resources melting in Hindu Kush and Himalaya has increased. This not only intensifies incidents such as Glacial Lake Outburst Flood (GLOF) but would also affect natural streams and springs in the northern parts of the country.
“Though there is a very little knowledge about permafrost in Pakistan, recently, a number of permafrost were found in the Karakorum mountain range near Khunjerab along the Karakorum Highway (KKH),” an official at the Pakistan Meteorological Department (PMD) told The Express Tribune.
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Permafrost is a thick subsurface layer of soil, rock or sediment of perennially frozen land. It is chiefly found in the polar regions or in other areas at high altitude or extreme cold. It has a higher density of carbon in it as well.
When permafrost melts, it has been linked with land sliding and erosion, the disappearance of lakes, and ground subsidence.
“This year, the snowfall season started late in December-January but more snow fell than the average snowfall over the last 10 to 12 years,” the PMD official said, adding that scientists and glacier experts are quite concerned about the consequences of a late snowfall.
“Previously, winter snowfall usually took over two to three months to melt. But when snowfall starts late, it is not properly compacted and it starts melting earlier at higher elevations,” PMD Director General Dr Ghulam Rasul told The Express Tribune.
“This means that the glaciers start melting faster than before.”
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When permafrost thaws, it releases carbon into the atmosphere in the form of carbon dioxide and methane. These greenhouse gases accelerate global warming which then speeds up the permafrost thaw.
Dr Rasul added that when permafrost starts melting, it causes GLOFs – when a body of water contained in a glacier is released due to the melting of the glacier – along with a corresponding increase in avalanches on mountains at high altitudes.
He added that in May 2017, a change had been recorded in the Khurdupin glacier which blocked the Shimshal River causing a new lake to be formed which was 300 metres long and 100 metres wide. The lake was first reported by locals who were taking their herd of yaks for grazing in a nearby valley.
However, the water levels in this newly formed lake were not rising most probably due to some drainage and thus did not pose a danger at this time. However, he said that the situation could turn for the worse if water levels in the lake continue to or in the event of a GLOF.
Dr Rasul added that he will soon lead a team of meteorologists to investigate the movement in the Khurdupin glacier.
The phenomenon of increasing permafrost melting is not exclusive to Pakistan. Earlier in February, a study published in Geology journal warned that more permafrost was decaying in northern Canada, Alaska, Siberia and Scandinavia.
Published in The Express Tribune, June 4th, 2017.