The ‘Rivers of Ice’ Phenomenon (Geography)
The ‘Rivers of Ice’ Phenomenon (Geography)Why In News:Ladakh’s large glaciers, sometimes called ‘rivers of ice’, are slowing down as surrounding mountains warm- a finding with major implications for the region’s water security and the Indus river system.Source: The Hindu, Page 18, 12 August 2026 - ‘Ladakh’s giant ‘rivers of ice’ are slowing as mountains warm’What are Glaciers and Why ‘Rivers of Ice’?Glaciers are large, slow-moving masses of ice formed by accumulated and compressed snow over long periods; because they flow under gravity, they are often called ‘rivers of ice’.Glacier flow speed depends on ice thickness, slope and basal temperature; warming can alter flow dynamics as the glacier’s mass balance turns negative.Slowing glacier flow is linked to reduced ice mass and thinning, driven by rising regional temperatures and altered snowfall patterns.Glacial melt regulates downstream river flow, especially in the lean (dry) season, making glacier health directly tied to water security for agriculture in Ladakh and downstream regions.Key Facts for PrelimsLadakh lies within the Karakoram-Himalaya glacial complex, part of the larger ‘Third Pole’ region (after the Arctic and Antarctic) holding the largest ice reserves outside the poles.Ladakh is home to major Himalayan and Karakoram glaciers, including the Siachen Glacier (the longest in India and second-largest outside the polar regions) and the Drang-Drung Glacier in Zanskar, which is a massive 23-km river of ice.Ladakh’s glaciers feed the Indus river system, a critical transboundary water source for India and Pakistan under the Indus Waters Treaty, 1960.The Karakoram Anomaly refers to the unusual phenomenon where some Karakoram glaciers have shown stability or slight growth despite global warming, unlike rapid retreat in the eastern Himalaya.Glacial Lake Outburst Floods (GLOFs) are a major hazard linked to glacier retreat, caused by sudden breach of moraine/ice-dammed lakes.In July 2025, a GLOF in Tibet triggered severe flooding downstream, damaging infrastructure and hydropower facilities in Nepal and highlighting transboundary flood risks for Himalayan regions, including India.