As scientists prepared to travel to the site in the high mountains north of Chamoli to ascertain the<\/span> cause of the <\/span>incident<\/b>, the scenario being most talked about was what glaciologists like to call a<\/span> GLOF, or glacial lake outburst flood..<\/span>\u00a0<\/span><\/p>\n \u00a0It is a reference to flooding caused downstream due to a breach in a glacial lake.<\/span>\u00a0<\/span><\/p>\n W<\/b>hat is GLOF? (glacial lake outburst flood)<\/b>\u00a0<\/b><\/p>\n A<\/span> GLOF event is where a naturally formed lake of glacial meltwater is breached, causing a<\/span> catastrophic release of large volumes of water downstream.<\/span>\u00a0<\/span><\/p>\n Glaciers on mountain tops and the sides of mountains accumulate ice from snowfall. This ice<\/span> melts in a process called ablation, adding water to downstream water bodies and rivers. The<\/span> process is continuous and is a part of the Earth\u2019s natural water cycle.<\/span>\u00a0<\/span><\/p>\n A<\/span>s a glacier retreats, i.e., reduces in size because of melting, it leaves sediments in the melted<\/span> freshwater in the form of clay and sand as well as rocks, boulders, and gravel. <\/span>These deposits<\/i><\/b> often create natural dams called moraines that contain meltwater within.<\/i><\/b>\u00a0<\/i><\/b><\/p>\n These natural dams or glacial lakes can overflow or be punctured\/breached, leading to flooding<\/span> downstream.<\/span>\u00a0<\/span><\/p>\n B<\/i><\/b>reaching of moraines can be triggered by avalanches, earthquakes or a natural<\/i><\/b> collapse of moraines due to excessive pressure from water. Also contributing to<\/i><\/b> GLOFs are anthropogenic (human-induced) activities such as deforestation and<\/i><\/b> p<\/i><\/b>ollution, which change local climate. Pollution exacerbates the potential for<\/i><\/b> disasters through the release of black soot particles, which can settle on ice,<\/i><\/b> absorbing more heat and accelerating melting.<\/i><\/b><\/p>\n Fragmentation of glacial ice can also trigger a breach in terminal moraines or dam boundaries,<\/span> either through direct impact or by displacement waves, which compromise the stability of the<\/span> dam. This is suspected to have occurred in Chamoli.<\/span>\u00a0<\/span><\/p>\n GLOF events are not unusual, but their impact depends on the size of the proglacial lake that<\/span> b<\/span>urst, and location. The breach can be caused by several reasons \u2014 in this particular case, for<\/span> instance, an avalanche was reported in the region two days ago.<\/span>\u00a0<\/span><\/p>\n B<\/i><\/b>ut while GLOF is being considered to be the most likely trigger for <\/i><\/b>Sunday\u2019s event<\/i><\/b>, there are<\/i><\/b> questions surrounding this possibility<\/i><\/b>. \u201cWe don\u2019t know of any big glacial lakes in this region.<\/span> An avalanche is quite common, and there could have been one, but an avalanche on its own<\/span> would not result in an increase in the flow of water in the river. The water has to come from a<\/span> source, and as of now, we do not know what this source is,\u201d said Professor H C Nainwal, a<\/span> glaciologist at the Hemwati Nandan Bahuguna Garhwal University in Srinagar, Uttarakhand.<\/span>\u00a0<\/span><\/p>\n Plus, there were no cloudbursts or earthquakes recorded in the past few days, so what caused the<\/span> glacial lake breach(if at all there was one) is a question mark.(so glof theory is a lil<\/span> weak)(landslide due to breaking of glacier looks more plausible<\/span>\u00a0<\/span><\/p>\n B<\/i><\/b>ut, was it really a GLOF? Some people say it wasn\u2019t.<\/i><\/b>\u00a0<\/i><\/b><\/p>\n Scientists studying satellite imagery from before & after the disaster say <\/span>a chunk of glacier appears to<\/i><\/b> have crashed down a mountain, triggering a landslide & subsequent floods.<\/i><\/b>\u00a0<\/i><\/b><\/p>\n International geologists and glaciologists studying satellite imagery say the cause of the <\/span>Chamoli<\/span> flooding disaster <\/span>in Uttarakhand appears to be a landslide and not a glacial outburst as widely<\/span> b<\/span>elieved.<\/span>\u00a0<\/span><\/p>\n Earlier reports stated that the flooding was caused by a glacial lake outburst flood (GLOF),<\/span> w<\/span>hich occurs when a natural lake is formed from a glacial ice melt and the lake is breached.<\/span> H<\/i><\/b>owever, available satellite images seemingly do not show the presence of a<\/i><\/b> glacial lake before the flooding event.<\/i><\/b><\/p>\n I<\/i><\/b>mages from Copernicus\u2019s Sentinel 2 satellite also showed the formation or<\/i><\/b> opening of a crack in the Nanda Devi glacier that is believed to have triggered the<\/i><\/b> landslide<\/i><\/b>\u00a0<\/i><\/b><\/p>\n In all likelihood, a steep, hanging portion of the Nanda Devi glacier broke off at Trishuli, in what<\/span> is called a \u2018rockslope detachment\u2019. <\/span>This potentially caused nearly 2,00,000 square<\/i><\/b> metres of ice to <\/i><\/b>drop 2 kilometres vertically<\/i><\/b>, causing a landslide, impacting the<\/i><\/b> valley floor and shattering instantly. <\/i><\/b>This debris, rock, and ice then flowed downslope in<\/span> the form of an avalanche, identified by the dust trail in the satellite imagery.<\/span>\u00a0<\/span><\/p>\n This avalanche flowed onto the glacier itself. Such intense flows of rock can cause<\/i><\/b> tremendous heat generation, melting ice and causing transient, slushy lakes<\/i><\/b> and\/or water flows.<\/i><\/b>\u00a0<\/i><\/b><\/p>\n These large volumes of ice, spanning nearly 3.5 km, would have further melted due to the heat<\/span> generated by the landslide and avalanche, leading to the huge volumes of water that flooded the<\/span> rivers.<\/span>\u00a0<\/span><\/p>\n LESSONS FOR HUMANITY(author\u2019s personal opinion, but kaafi<\/i><\/b> relevant)<\/i><\/b>\u00a0<\/i><\/b><\/p>\n (so, all these points can be said, when asked, \u201cwhat went wrong\u201d<\/b> or \u201cwhat could be done\u201d)<\/b>\u00a0<\/b><\/p>\n Such disasters are as much man-made as they are acts of nature<\/i><\/b>.<\/span>\u00a0<\/span><\/p>\n An unusually heavy burst of rain, or the <\/span>unpredictable behaviour of a glacier(likely to have<\/i><\/b> h<\/i><\/b>appened in this case)<\/i><\/b>, or even an earthquake, <\/span>would have far less damaging effects if the<\/i><\/b> natural forests had been kept intact, if the roads had been built with more care, if no dams had<\/i><\/b> been designed or built, if the siting of homes and hotels had kept in mind the distinctive ecology<\/i><\/b> of the Himalaya.<\/i><\/b>\u00a0<\/i><\/b><\/p>\n Because carelessly-constructed roads and dams lead to large amounts of debris being dumped,<\/i><\/b> h<\/i><\/b>ill rivers become more violent and turbulent.<\/i><\/b><\/p>\n Because permissions to build hotels and buildings are given regardless of local needs and<\/i><\/b> constraints, hillsides become weaker and more likely to collapse when threatened by storms and<\/i><\/b> floods. (this is impppppppp)<\/i><\/b>\u00a0<\/i><\/b><\/p>\n The loss of life and livelihood that results is therefore as much a consequence of such faulty<\/i><\/b> p<\/i><\/b>olicy-making, and of corruption and human greed, as it is of the “wrath of nature” per se.<\/i><\/b>\u00a0<\/i><\/b><\/p>\n For all these reasons, there should be an absolute moratorium on dam projects in the Himalaya<\/i><\/b>\u00a0<\/i><\/b><\/p>\n Even outside the Himalaya, we need to follow a wiser and more environmentally-responsible<\/span> pattern of development. India’s high population densities, and the fragility of tropical ecologies,<\/span> mean that we cannot – and must not – mechanically imitate the energy-intensive,<\/span> capital-intensive model of industrialization adopted in the West. We must seek to achieve<\/span> growth and prosperity with less resource-extractive and more sustainable methods.<\/span>\u00a0<\/span><\/p>\n A<\/i><\/b> crucial lesson of this latest Himalayan tragedy is that for us to adopt a more sustainable path,<\/i><\/b> elected politicians must be more willing to take advice from scientific experts, and be less<\/i><\/b> amenable to bribery by deal-makers. At present, the decision on where and how to build a port,<\/i><\/b> or highway, or dam, or airport, is made by three sets of people – ministers, bureaucrats, and<\/i><\/b> contractors. Those who know hydrology, or traffic management, or energy planning, or mountain<\/i><\/b> ecology, are rarely (if ever) consulted, even if they might be close at hand.<\/i><\/b> That the neta-babu-thekedar complex breeds corruption is well-known; that it generates<\/i><\/b> inefficiency, incompetence, and environmental disasters is less widely recognized.<\/i><\/b> (IMPPPP SHIT)<\/i><\/b>\u00a0<\/i><\/b><\/p>\n (UNIQUE POINT THIS)<\/i><\/b>\u00a0<\/i><\/b><\/p>\n The fuller and deeper decentralization of political decision-making is likely to aid more<\/i><\/b> sustainable (and equitable) economic policies. The advantages of local control over natural<\/i><\/b> resources are abundantly demonstrated by the <\/i><\/b>success of Community Forest Management in<\/i><\/b> the Gadchiroli district of Maharashtra<\/i><\/b>. Here, when villagers were given control over mixed<\/i><\/b> forests earlier managed by the state bureaucracy, these forests grew much thicker, while<\/i><\/b> g<\/i><\/b>enerating a steady stream of income and employment as well.<\/i><\/b>\u00a0<\/i><\/b><\/p>\n The Gadchiroli model should be emulated in other forested districts of central India, where it<\/i><\/b> might likewise regenerate nature, renew the economy, and ameliorate tribal discontent. And its<\/i><\/b> lessons must be heeded more broadly. Wider consultation, a greater devolution of financial and<\/i><\/b> decision-making powers to panchayats and municipalities, is likely to lead to wiser and better<\/i><\/b> p<\/i><\/b>olicies in other sectors too.<\/i><\/b><\/p>\n To structure your\u00a0CAT online preparation<\/a>\u00a0in an efficient way consider joining iQuanta which is a\u00a0top online cat coaching<\/a>\u00a0institute and being a part of the iQuanta CAT 22 Course.![\"\"](\"https:\/\/www.iquanta.in\/blog\/wp-content\/uploads\/2021\/12\/WhatsApp-Image-2021-12-16-at-4.09.20-PM-1.jpeg\")
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