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Greetings, friends! A very unfortunate news has come from Uttarakhand’s Chamoli district Allegedly, a portion of the Nanda Devi glacier broke off which triggered a sudden flood At the time of making this article, according to latest update, at least 15 people have died and close to 100 people are still missing. And two power plants were also extensively damaged by this disaster This is not the first time such a disaster has occured It serves as a grim reminder of the disaster of 2013 And this is also not the last time that such a disaster has taken place Infact, disasters like these will become more frequent as well as more deadly in the coming times due to climate change So, I feel it is extremely important to make a video on it so that we can be prepared for the upcoming times There is still a lot of uncertainty around what exactly caused the disaster and what are the reasons behind it but many experts believe the reason behind this is a phenomenon called GLOF glacial lake outburst flood Before I explain to you about glacial lake outburst flood, let us start with the basics:
What is a glacier?
You all might already know broadly, what a glacier is. A picture like this might pop up in your mind but what exactly is a glacier? Glacier is basically ice It is a huge mass of ice that has collected over thousands of years One of the oldest glacier dates back to 30,000 years! It’s almost as if the ice of this glacier hasn’t melted for thousands of years! They’re found at places with temperatures so low that more and more ice and snow accumulate and melt and ice does not get the opportunity to melt For example, you will find glaciers on mountain tops or in places like Iceland and Alaska So, a glacier is such a heavy and massive mass of ice that it begins to move because of it’s weight You heard that right- glacier is basically moving ice or you could say- “flowing ice” Just like rivers are flowing water, glaciers are flowing ice When these glaciers flow down to the bottom of the mountains, the temperatures are higher and the ice melts and eventually, these glaciers lead to the formation of rivers These glaciers give rise to rivers. One interesting thing to note is that whenever a glacier flows, then the land beneath it- all the rocks, mud and gravel- are carried along with the glacier Glacier acts like the conveyor belt in a way- just like a conveyor belt carries suitcases along in the airport, the glacier acts like a similar belt for these rocks and the mud It picks them up and dumps them forward, in one sense Due to this reason, the path of the glacier is clearly visible on the land through which the glacier passes Lines are carved out and the rocks get arranged in a specific way This is called the formation of moraines These moraines are visible both on the sides as well as the end of the glacier The moraines on the end are called terminal moraines .
Secondly, when glaciers melt, glacial lakes are formed at their ends if they do not give rise to rivers And this lake forms the end of the glacier- the high temperature melts the ice into water Take a look at the diagaram:Glacier, glacial lake and at the moraines at the end of it The moraines are a kind of natural dam that the glacier itself has created We all are aware that the melting rate of the glaciers has been rising exponentially due to the climate change Since more and more glaciers are melting, it is obvious that more and more glacial lakes will get formed in the places where glaciers are found Sometimes, it so happens that the moraines/natural dam of the glacier gets breached The breach can be caused by several reasons — due to landslides, avalanches, small earthquakes etc It can also happen that a part of the glacier breaks off and falls into the lake which leads to a sudden increase in the volume of the glacial lake which leads to the breach of the moraine/natural dam. Once that happens, all the water in the glacial lake flows down and creates a flood like situation And this is called a glacial lake outburst flood. which, according to some experts, is what happened in the Uttarakhand disaster But some experts believe otherwise Professor H C Nainwal, who is a glaciologist says that they don’t know of any big glacial lakes in this region Another point of this not being the reason for what happened could be that it is wintertime right now The glacial lake outburst floods take place mostly in summers when the temperatures are high and more water collects in the glacial lakes, which could eventually trigger floods So, if the glacial lake outburst flood is not the reason behind what happened, what else could it have been?
Another possibility that is being put forward is that the part of the Nanda devi glacier that broke off actually fell from a great height So, when the part of the glacier fell down from such a great height, then a huge amount of heat was generated from it’s impact which melted the ice, triggered an avalanche and a landslide and a large amount of ice got converted into water suddenly, which triggered the flash floods This could have been one possibility A third possible scenario that was put up was that it is possible that an avalanche or a landslide created an obstruction by arranging rocks in a manner that resulted in a natural/ makeshift dam-like situation. And this natural dam might have breached triggering the flash floods This might explain why glacial lakes were not spotted in the region earlier but whatever the case might be, there is one thing for sure- humans have had a direct/indirect impact that led to these natural disasters The first and the biggest reason is definitely climate change due to which more and more glaciers are melting with more intensity More and more glacial lakes will get formed which will increase the chances of floods like these even more in the coming times .
A research by the Kathmandu-based International Centre for Integrated Mountain Development has said that 36% of the volume of glaciers in the Himalayan region will be gone by the end of 2100 As the climate change increases, the average change in the temperature of the earth is increasing the speed of melting is increasing at the same rate Another research has observed that the melting rate of the glaciers between the years 1975 to 2000, has doubled in the years after 2000 The solution of this sounds quite simple, but it might take us years, even decades to achieve We will have to stop the climate change .
All the countries will have to abide by the pledges in the Paris Climate Agreement that has been signed by almost all the countries of the world The best possible attempts should be made to switch to electric cars and renewable energy and we will have to curb the carbon emissions from the different sources Apart from climate change, there is another reason which has a more short term and direct effect on nature. The environmental destruction that we see- someplaces, it is in the form of infrastructure projects like making more dams and further restricting the natural flow of the rivers in other places, forests are cut down to lay roads One good example of this would be the government’s Char Dham Highway Project which is currently under construction Several experts and ecologists have raised questions on it as it is being constructed in an eco sensitive zone which could be extremely detrimental for the ecology of Uttarakhand in the coming times Infact, some experts believe that the government made use of legal loopholes and by passed the Environmental Impact Assessment report- which assesses the impact of the construction of the highways and other infrastructure projects on the local environment The logic here is quite simple- if you cut down trees to lay highways, the changes of landslides would increase The roots of the trees bind the soil together and act as a barrier against the avalanches and landslides The Supreme Court though, has tried to reduce the environmental damage to some extent by passing an order that would narrow down the width of the highway The solution in cases like these is that the public should raise their voice whenever they see the government undertaking projects or development in which the harms caused by the project outweigh the benefits of the project Be it the example of the Aarey forests, or the Mollem example in Goa or the Char Dham project Additionally, there is a third, albeit technical solution to avoid such problems that specifically addresses the problem of the glacial lake floods If the formation of glacial lakes are observed and assessed beforehand and if it is predicted, using mathematical models- which glacial lake is being formed where and which glacial lakes do not have a strong moraine formation which could potentially point to the risks of the glacial lake outburst floods in the region, Then there are simple, engineering related solutions for such scenarios Instead of waiting for the glacial lake outburst, we could start draining the lake Canals could be built on the sides of the lake which would drain the water from there and so that the water does not accumulate to trigger floods someday For these technical solutions, the government will have to improve its remote sensing technology in order to identify the sites of the formation of the glacial lakes and then make use of computer simulations to see where the risk is the most and what can be done to mitigate it The only thing is that we will have to start working on these solutions starting today so that disasters like these can be avoided in the future And so that we remain prepared for them even if they do occur What is your opinion here? Write down in the comments below I hope you would have liked this small, educational article .
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