Uttarakhand flood | What are glaciers, how do they form, and more

Uttarakhand’s Chamoli district witnessed an avalanche and massive flooding on February 7 after a portion of the Nanda Devi glacier broke off causing overflow of the Alaknanda river system — consisting of the Alaknanda river, the Dhauli Ganga and the Rishi Ganga — all tributaries of the Ganga. But what are glaciers and how do they form? Here’s everything you need to know about glaciers, one of the most powerful geological agents that shape the Earth’s surface as they move.