Himalayan glaciers disappearing fast

LUCKNOW: Glaciers - huge masses of snow and ice - have had a massive impact on the development of earth and now, they are disappearing at an alarming rate.
"There are more than 11,000 glaciers in the Himalayan region and they are all receding, albeit at different rates. An enveloping factor for this process is global warming," says Dr DK Bhatt, Deputy Director General (Northern Region), Geological Survey of India, Lucknow.
In fact, the Gangotri glacier, parent of the Ganges river, was receding at the rate of 28.33 metre per year between 1990-96, leaving a vacant space of 22,370 square metre per year.
"Period of glaciation began 1.8 million years back during the Pleistocene age and for the last 10,000 years, we have moved into Holocene age, which is the period of warming, leading to excess melting of glaciers," explains Dr Bhatt.
But the debate does not stop at global warming. "Usually global warming is considered the main reason, but it is not so. According to a study by the United Nations, the temperature in the Leh region has decreased by 0.04 degrees in 125 years, but the glaciers there too continue to melt," informs Dr Dhruv Sen Singh, department of geology, Lucknow University.
According to Dr Singh there are reasons like wind, mass movement, supra-glacial lakes and flash floods which result in melting of glaciers.
"There are factors like crevasses (deep cracks) in the glaciers, which allow the sunlight to reach inside the glacier making it melt faster. Lineament results in huge chunks of the glaciers breaking away thus reducing the size of the glacier," says Dr Singh.
On the other hand Dr Bhatt believes that decrease in temperature in Leh region could be a local phenomenon. "The winds could have a cooling affect. Also when a region is in the shadow of a higher mountain, it leads to a cooling effect as the sunlight doesn''t reach there," explains Dr Bhatt.
All seem to agree on one major and almost haunting fact, that the glaciers are fast disappearing and could be extinct soon.
"Many small glaciers have already disappeared. Gangotri being a huge glacier, spread over an area of 143.58 square kilometre and about 30 km long, will not disappear that soon," says Dr Bhatt.
But the disappearing glaciers are posing a threat to all the rivers that are dependent on them. "There will be shortage of river water as the glaciers decrease, but we cannot say that Ganga will also become extinct with the Gangotri glacier because the river is fed by various other glaciers and also has many tributaries joining it. But there is definite threat," Dr Bhatt points out.
Climate of the region and further of the entire country will be affected as receding glaciers will lead to a change in the wind circulation pattern. "Wind flows from warm to cold region, but as glaciers shrink the circulation will also change. This will also affect the monsoons," says Dr Bhatt.
And lastly, the entire Himalayan terrain will be under the threat of erosion. "The soil in the mountain region is very loose and even slight vibrations will cause landslides with no glaciers or vegetation to hold on to the soil," says Dr Bhatt.