<p><strong>Syllabus section: Geography and disaster management</strong></p>

<p><strong>Why in News?</strong><br />
A glacial lake burst, a cloud burst or an avalanche, the impact of climate change or &ldquo;development&rdquo; &mdash; scientists are not sure what triggered the sudden surge of water near Chamoli in Uttarakhand Sunday morning that briefly raised fears of a repeat of the 2013 disaster in the state.</p>

<p><strong>About glacial lake burst:</strong><br />
&bull; A GLOF is a type of outburst flood that occurs when the dam containing a glacial lake fails.<br />
&bull; An event similar to a GLOF, where a body of water contained by a glacier melts or overflows the glacier, is called a J&ouml;kulhlaup.<br />
&bull; The dam can consist of glacier ice or a terminal moraine.<br />
&bull; Failure can happen due to erosion, a buildup of water pressure, an avalanche of rock or heavy snow, an earthquake, volcanic eruptions under the ice, or a glacier collapses into it.</p>

<p>Retreating glaciers<br />
&bull; Retreating glaciers, like several in the Himalayas, usually result in the formation of lakes at their tips, called proglacial lakes, often bound only by sediments and boulders.&nbsp;<br />
&bull; If the boundaries of these lakes are breached, it can lead to large amounts of water rushing down to nearby streams and rivers, gathering momentum on the way by picking up sediments, rocks, and other material, and resulting in flooding downstream.</p>

<p><strong>Source: Indian Express</strong><br />
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