What is a hanging glacier?

Earlier this month, a glacier broke off at Joshimath in Uttarakhand’s Chamoli district, causing an avalanche in Raini village in Tapovan area. The avalanche (a rapid snowslide) was soon followed by flash floods due to a massive rise in water levels in the Dhauliganga river, which buried houses and people along its banks. The devastating flood damaged two hydropower projects, bridges, trapped workers in underground tunnels and killed at least 36 people (at the time of going to press).

A team of scientists at the Wadia Institute of Himalayan Geology investigating the incident suggested that the collapse of a hanging glacier triggered the deluge. This hanging glacier was adjacent to Raunthi glacier, which originates from a remote and inaccessible peak called Mrigudhani (6.063m above sea level). The glacier was hanging on a slope, held up by a mass of rock.

Scientists say that this portion could have weakened over a period of time due to freezing and melting and would have broken off hurtling down the steep mountain slope and falling into a narrow stream. As the water level increased in the stream, it burst. The rushing water breached the dam below and caused massive floods downstream, they explained. But what is a hanging glacier? Let’s find out

What are glaciers?

Glaciers are slow-moving ice masses formed over many years of accumulation of snow – the snow that escaped melting and sublimation over the years. Glaciers flow due to stress from their own weight. They erode rocks on their way and form crevasses.

Glaciers store water in the form of ice during the colder seasons and release it during warmer seasons by way of melting. This serves as a water source for humans, animals and vegetation. There are some 10,000 glaciers in the Himalayas, and Uttarakhand alone has up to 1,495 glaciers.

What are hanging glaciers?

Not all glaciers reach the ocean or a valley floor. Some terminate halfway to the main glacier surface, most often at a diff. The sudden avalanches caused by hanging glaciers often put the area beneath them at risk.

Scientists attributed climate change to the weakening of the hanging glacier that caused the flood in Uttarakhand Rapid temperature changes lead to freezing and thawing of ice, and thereby glacial fractures over time. When temperatures rise, glaciers lose ice faster than they accumulate. This ice melt can lead to the retreat of glaciers and affect the entire ecosystem. Many glaciers around the world are receding due to the warming climate.


Picture Credit : Google