Glacial lake outburst flood (GLOF)
A glacial lake outburst flood (GLOF) is a release of meltwater from a moraine- or ice-dam glacial lake due to dam failure.
Enrich Your Learning:
GLOFs often result in catastrophic flooding downstream, with major geomorphic and socioeconomic impacts.
GLOFs have three main features:
They involve sudden (and sometimes cyclic) releases of water.
They tend to be rapid events, lasting hours to days.
They result in large downstream river discharges (which often increase by an order of magnitude).
Why are GLOFs important?
Some of the largest floods in Earth’s history have been GLOFs.
They have caused large-scale landscape change5, and even altered regional climate by releasing huge quantities of freshwater to the oceans.
Today, GLOFs pose a risk downstream communities and infrastructure.
There are two main settings in which glacial lakes form: (1) behind moraine dams, and (2) behind ice dams.
GOLF in India:
In the Indian Himalayan region, the first glacial lake outburst flood was reported when the 1926 flood caused by the Shyok glacier in Jammu and Kashmir.
Hindu Kush-Himalayan region does not have any early flash flood warning system in place despite being surrounded by over 8,000 glacial lakes, around 200 of them potentially dangerous.
North Indian states that fall in this region include Uttarakhand, Himachal Pradesh and Jammu and Kashmir, are surrounded by about 200 potentially dangerous glacial lakes formed by glacial melt and all affected by the recent extreme rainfall event.