Understanding the rapid retreat of the Pensilungpa Glacier in Ladakh’s Zanskar Valley is critical to our knowledge of climate change and its impact on our planet. A recent study by the Wadia Institute of Himalayan Geology (WIHG), has discovered that the glacier’s decline is due, in part, to an increase in temperature and a decrease in winter precipitation.
The Findings
The WIHG research brought forth many findings regarding the rate of the glacier’s decline. Notably, it showed that the glacier is retreating at an average rate of 6.7 plus/minus 3 metres per annum. Glaciers retreat when their ice melts more quickly than snowfall can accumulate and form new ice.
Importance of Debris Cover
The study also highlighted the significant influence of debris cover on the mass balance and retreat of the glacier’s end point, particularly during the summer. The data for the years 2016-2019 showed a negative trend in the mass balance, with a small accumulation area ratio.
Rising Air Temperature’s Impact
A continual rise in air temperature in accordance with the global trend could lead to an increase in the glacier’s melting. It is also likely that the precipitation pattern at higher altitudes will change from snow to rain during summer periods. This change could influence both the summer and winter precipitation patterns.
Potential Consequences
The research emphasises the potential impacts on human life. The retreat of the Pensilungpa Glacier could affect water, food, and energy security and agriculture, including soil loss due to erosion, landslides, and floods. The formation of glacial lakes due to accumulated melted ice could result in Glacial Lake Outburst Floods and even shift the global climate by introducing freshwater into the oceans, altering their circulation.
Remnants of Glacial Retreat
The glacial retreat leaves behind boulders and masses of rocky debris and soil, known as glacial moraines.
National Mission for Sustaining the Himalayan Ecosystem
The National Mission for Sustaining the Himalayan Ecosystem is one of the eight national missions under the National Action Plan on Climate Change. This mission focuses on the sustaining and safeguarding of the Himalayan ecosystem.
About Glaciers
Glaciers are large, perennial accumulations of crystalline ice, snow, rock, sediment, and water that move downhill under the influence of their own weight and gravity. They are important indicators of changing climate. Interestingly, of all the water on Earth, only 2.1% is in glaciers while 97.2% lies in oceans and inland seas.
Glacial Formation Conditions
For a glacier to form, the mean annual temperatures must be close to freezing. Winter precipitation has to produce significant accumulations of snow, and temperatures for the remainder of the year should not result in the complete loss of the previous winter’s snow accumulation.
Zanskar Valley and its Glacial Landforms
The Zanskar Valley, home to the Pensilungpa Glacier, is a semi-arid region located in the northern flank of the Great Himalayas. The Zanskar Range separates Zanskar from Ladakh and acts as a climatic barrier protecting both regions from most of the monsoon. As a result, these areas enjoy a pleasantly warm and dry climate during the summer. The valley is known for the Marbal Pass and Zojila Pass, as well as several rivers including the Hanle River, Khurna River, Zanskar River, Suru River, and Shingo River, which join the Indus River.