There are speculated scores of reasons behind the glacier breach while the reports about an avalanche hitting the region are also surfaced. Scientists across the world, initially grope in the dark while pondering about the possible reasons behind the gory calamity that has hit our state of Uttarakhand as of yesterday. Whether such was a glacial lake burst, a cloudburst, an avalanche, the impact of climate change or simply the price poor dwellers paid for infrastructure development. Thoughts, knowledge, skills, opinions and expertise are pieced together in an effort to uncover the possible reasons behind abrupt rise in water near Chamoli that proved so much ghastly claiming 150 lives and similar number is missing too.
The term GLOF has come into light amid all such ruckus as the possible cause of this, which stands for Glacial lake outburst flood, which is about downstream flooding as a result of glacial lake breach.
There are plethora of glaciers present in the Himalayas and lakes are formed at their tips and glaciers in retreating form, is called proglacial lakes which are rounded up by sediments and boulders only. Now, when the limits of such lakes are violated, a huge surge of water occurs which flows down to streams and rivers flowing close by and which still picks up pace on the way down, including rocks, sediments and such solidified stuff and eventually, takes the shape of a flood, horribly devastating.
Events related to GLOF are common to sight but the magnitude of their impact (and devastation caused by) has close association with the size which that proglacial becomes of, that eventually rips off, while the location and terrain also constitute to be standing factors. Now, as far as its frontier violation is concerned, there could be scores of reasons and in this particular case, the region also witnessed an avalanche just a couple of days ago.
Now, as the most absolute cause behind Sunday’s disaster, even though GLOF is stressed upon as the major cause, but still, questions and doubts are being raised over this claim. At this, a prominent glaciologist at the Hemwati Nandan Bahuguna Garhwal University in Srinagar, Uttarakhand, Prof H.C. Nainwal opines, “We don’t know of any big glacial lakes in this region. An avalanche is quite common, and there could have been one, but an avalanche on its own would not result in an increase in the flow of water in the river. The water has to come from a source, and as of now, we do not know what this source is”.
“We would have to visit the area to find out what exactly happened. Till then, we can only speculate”.
Then, another viewpoint is shared by Argha Banerjee, who is a glaciologist too at the Indian Institute of Science Education and Research (IISER), Pune who pinpoints the presence of glacial lake in the region which scientists might not have noticed. Prof Banerjee confirms, “There are hundreds of such lakes all over the place. We know about many of them, but it is possible that there is one that we do not know about. After today’s event, I started looking at the satellite images, and I couldn’t find any glacial lake in that area. But maybe, if we look at higher resolution satellite images, we would find one”. Prof Banerjee also revealed several instances where glaciers contained lakes inside them and which went unnoticed in satellite images.
He also enlightened,” But if there are indeed no glacial lakes in that area, then Sunday’s event would seem to be a bit of a surprise”.
Now, considering the timing of the event also becomes crucial, as the one, we can hardly expect anything like an abrupt commotion causing surge of water or even a cloudburst, in these months.
Now, we have an insight put forth by Professor A P Dimri who happens to be at School of Environmental Sciences at Jawahar Lal Nehru University, Cloudburst would be a rare event during this time of the year. It does look like a GLOF event right now”. But then, other wide range of possibilities can never be overlooked too, as per suggestion made by Prof Banerjee.
Professor Banerjee sheds light further, “It is possible that an avalanche or a landslide created an obstruction in the flow of the river or streams in the upper mountains, resulting in a makeshift dam-like situation. When the pressure of the flowing water became large, the dam probably gave away, leading to a sudden gush of water. These are just the possible scenarios. We would know the exact reason only after reaching the site. It might take a day or two.”
Now to search for the real causes, Wadia Institute of Himalayan Geology, Dehradun, arranges a visit by 2 teams comprising senior scientists to the region, who would have reached today, i.e. Monday,. While broadening our horizon, one cannot rule out climate change and unreasonable construction in an ecosystem that is deeply nature-sensitive otherwise and due to which widespread devastation was caused in 2013 whose memories are still afresh in minds.
Till now, however, no direct connection about the construction and man-made activities in the region has come to light, that might have triggered the carnage, neither do the role of big dams in the area can be sidelined too and still, environmentalists’ complaints and climate change, as the significant factor, can hardly be crushed under gross ignorance, as we have witnessed proglacial lakes.
Notwithstanding, scientists are of the opinion that any shattering glacier can hardly result in such a huge unpleasant event. Also, glaciers are not thought to be ripped-off in a way that we see frequently in polar region for ice-sheets. Some of the snow expanse from the tip of the nearby glacier can surely flow down, but still, huge gush of violent water flows are not resulted which might cause incidents of such nature and degree.