Climate change, tectonic movement modifying the course of Himalayan glaciers: study


As climate change worsens the melting of glaciers across the world, scientists have for the first time spotted a rare event in Himalayan glaciers. It abruptly changed its main course, and scientists attribute it to climate change and tectonic movements.

Indian researchers were studying an unnamed glacier in the upper Kali Ganga valley of Uttarakhand’s Pithoragarh district when they noticed that the glacier had suddenly changed its usual course due to a cumulative influence of climate and tectonics. . The researchers believe that the glacier’s abnormal behavior suggests that not only is climate a controlling factor, but tectonics also play an important role in glacial watersheds.

The change in glacier movement further confirms the findings of the February 7 disaster on the hilly terrain of Chamoli in which more than 200 people were killed. Scientists said the tragedy began atop the six km-high Ronti Peak, where a large mass of ice and rock dislodged from the slopes, triggering a massive landslide that turned into mud and in debris flow, causing destruction in its path.

The debris flow generated a powerful blast of air that flattened nearly 20 hectares of forests.

The incident showed how the rock mass on which the glacier sat gradually weakened due to weathering, meltwater percolating into the joints, crevices, freezing and thawing, falls snow, overload and progressive tectonic forces leading rocks to mechanical disintegration over time. and detached from the bedrock.

Photo: Ministry of Science and Technology

The new findings suggest that the Himalayas are an active and very fragile mountain range where tectonics and climate play a critical role. The new study by a team of scientists from the Wadia Institute of Himalayan Geology (WIHG), Dehradun, has been published in the ‘Geoscience Journal’.

Scientists reported that the unnamed five-kilometer-long glacier, which covered an area of ​​four square kilometers in the Kuthi Yankti Valley (a tributary of the Kali River) had suddenly changed its main course. The northeast moving glacier was truncated and forced to move southeast to eventually merge with the adjacent glacier named Sumzurkchanki due to tectonic forcing.

“The study will help understand the glacial-tectonic interaction and will provide key information for future studies,” the document said.

The researchers used satellite images, a topography sheet, and Google Earth imagery to assess that the glacier had been affected by an active fault and climate change, as an active fault produced a fault escarpment measuring approximately 250 m in height. height with a north dip of 6.2 kilometers in length and trends to NW-SE.

“This is one of the unique behaviors of the glacier, and no such observations have so far been reported on this type of glacial kinematics. The study indicates that climate is not the only triggering factor disasters in the Himalayas, which is an active mountain range, but tectonics also play an important role in glacial watersheds, ”the Ministry of Science and Technology said in a statement.

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