Wadia Institute of Himalayan Geology (WIHG) in Dehradun, which is an autonomous body under the Department of Science and Technology (DST), discovered that there has been a seasonal advancement in 220 surging or surge-type glaciers found in the Karakoram Range of Ladakh.
Understanding Surging Glaciers
Surging or Surge-type glaciers are unique types of glaciers that have recorded progress in volume and length over time. Interestingly, these glaciers contradict the general trend seen in most Himalayan glaciers that have significantly reduced in both volume and length in recent years.
Researchers found out that surging glaciers constitute about 40% of the total glaciated area of the Karakoram range. Unlike normal glaciers, surging glaciers do not flow at a fixed speed. Instead, their movement is characterized by cyclical flow instabilities.
Scientists have categorized the fluctuations of such glaciers into two stages: the Active Phase (or surge phase), which is a short period of rapid flow, and the Quiescent Phase, a long period of slow flow or stagnation. It was noted that surges during winter are more regulated due to the low quantity of meltwater that flows irregularly underneath the glaciers. However, the surging halts during the summer because the melted water flows in a channeled manner.
The Importance of Studying Surging Glaciers
Surging glaciers can pose a significant threat to human settlements and infrastructure as they can destroy villages, roads, and bridges. They can also move across a river valley, leading to the formation of ice-dammed lakes. These lakes can result in disastrous outburst floods. Thus, vigilant monitoring of glacier surges, ice-dammed lake formation, and drainage is vital.
Glaciers: A Brief Overview
Glaciers are essentially extensive masses of ice that move as sheets over the land. They are referred to as continental glaciers or piedmont glaciers when a vast sheet of ice spreads over the plains at the foot of mountains. When these ice sheets linearly flow down mountain slopes in broad trough-like valleys, they are known as mountain and valley glaciers.
The movement of glaciers is relatively slow compared to water, ranging from a few centimeters to a few meters per day. The primary reason glaciers move is due to the force of gravity. Moreover, glaciers can cause substantial erosion due to the friction generated by the immense weight of the ice.
Large-sized angular blocks and fragments are often plucked from the ground by glaciers and dragged along the valley floors or sides, causing considerable damage through abrasion and plucking. Glaciers have the power to cause substantial damage to even un-weathered rocks, reducing high mountains to low hills and plains.
Over time, as glaciers continue to move, debris gets relocated, divides get lowered, and eventually, the slope becomes so reduced that the glacier halts its movement. This leaves behind a landscape characterized by low hills and vast outwash plains, along with other depositional features.
Last Modified: February 7, 2024