Uttarakhand Glaciers Melting Rapidly: Study Flags Threats Days After Nepal Disaster

Glaciers in Uttarakhand are now under threat as rising temperatures worldwide are directly affecting the Himalayan region. A recent study has found that 23 major glaciers in Uttarakhand are melting rapidly. While the pace of the melting is driven by rising temperatures due to climate change and global warming, a second factor is each glacier's shape, slope, and debris load; in other words, its geographical setting.

The study happens to have been published just days after Nepal's deadly flood, which killed over 1,400 people, was linked to a glacier's melting. Over the past few years, chunks of ice are breaking off big glaciers and sweeping down the valleys, causing destruction in populated areas. This is why scientists, environmentalists and governments are now focusing on the Himalayan glaciers at risk, since they supply water for irrigation, drinking and hydropower projects not only in India but in neighbouring countries. Major rivers such as the Ganga, Bhagirathi, Sutlej, Ravi, Indus, Brahmaputra, Yamuna, Alaknanda and Mahakali originate in the Himalayas.

Uttarakhand's terrain is almost identical to Nepal's, as it has the glaciers Gangotri, Alkapuri, Milam, Pindari, Khatling, Satopanth and Bhagirathi, besides hundreds of others whose rate of melting has risen sharply in recent years.

The research paper was published in the journal 'Discover Geoscience' by Jyoti Kumari, Girish Chandra Kothiyari, Atul Kumar Patidar and Manish Mehta, scientists at the Wadia Institute of Himalayan Geology. Records of 23 glaciers were examined, and the cause of each glacier's melting was identified.

For instance, for the Shankulpa glacier in Pithoragarh district, a seven-decade record shows the glacier melted 518 m, at a rate of 6.8 m per year. Bandarpunch glacier in Uttarkashi, as per a 39-year record (1960-1999), showed it melted at a rate of 25.51 m per year.

Chorabari glacier in Rudraprayag, as per the 1962-2010 data, showed it melted 327 m, at a rate of 6.8 m a year.

The map that's part of the research paper, showing the key glaciers.

Khatling glacier in Tehri melted at a rate of 88 m a year.

Gangotri glacier was studied twice. The first, 69-year record (1935-2004) showed it melted at a rate of 22.02 m a year. The second, six-year record showed it melted at 21.3 metres a year.

Dokriani glacier in Uttarkashi melted at 21 metres a year; Bhagirathi glacier at 3.7 m a year; Satopanth in Chamoli district at 26.45 m a year; Tipra glacier, 14.41 m a year; Dunagiri, 9 m a year, and so on.

Among the more alarming ones were Milam glacier in Pithoragarh, melting at a rate of 32 to 37.8 metres a year; North Nanda Devi at a rate of 22 m a year; Ramani at 32 m a year.

Pindari glacier was studied twice. The first study, a 121-year record (1845-1966), showed it melted 2,840 m, at a rate of 23.4 m a year. The second, an 18-year record (2000-2018), shows it melted 825.23 m, at a rate of 45.85 m a year.

Khatling, Milam, Gangotri, Satopanth, Ramani and Jaundhar are the major Uttarakhand glaciers whose rate of melting has been very rapid. Of these, Milam and Khatling have retreated fastest over the past several years.

The historical records of all these glaciers were studied, and it was found that debris-covered glaciers are melting at a few metres a year, while clean-ice glaciers are melting much faster.

If glaciers continue to melt at this rate, there is a risk of rising sea levels eventually. The risk of natural disasters, such as glacial lake outburst floods (GLOFs), avalanches and debris flowing down from higher altitudes, has also increased. The rate of glacier melt has risen sharply since 2000. One reason for the melting is rainfall at altitudes of up to 4,000 m, where snow used to fall but now it rains. The summer season has also lengthened, winter snowfall has declined sharply, and the snow that does fall does not get time to consolidate.