Ladakh Glaciers Losing Speed as Ice Melts, New Study Warns
A recent study has found that glaciers in the Zanskar Himalayas in Ladakh are losing speed, with implications for water availability in the region over the long term.
The phrase "moving at glacial pace" is often used to describe slow-moving processes. However, new research suggests that glaciers in the Zanskar Himalayas in Ladakh are moving even slower than before.
Glaciers in the region are not stationary, but their mass is slowly pulled down by gravitational forces over time. The speed at which glaciers descend can be used as an indicator of their health. According to Manish Mehta, a scientist and glaciologist at the Wadia Institute of Himalayan Geology, glaciers have two parts: the crown at the top, where ice and snow are accumulated, and the snout or toe at the bottom. The accumulation of ice at the crown pushes the glacier down, increasing its velocity.
However, in recent times, glaciers are losing their mass in both the upper and lower zones. With less mass, there is less movement. A study published in The Cryosphere journal found that glacier velocity in the Zanskar Himalayas decreased by 16% from 1992 to 2023.
## Region-wide slowdown
The Zanskar Himalayas cover an area of 7,000 square kilometres, with elevations ranging from 3,500 to 7,135 metres above sea level. The region is home to around 1,755 glaciers, but the study only observed 12 glaciers. The researchers used satellite imagery to calculate glacier velocity and determine glacier thickness.
The study found that between 1992 and 2000, all observed glaciers showed an increase in glacier velocity, indicating a healthy mass balance. However, between 2001 and 2023, the velocity of most glaciers slowed. Glaciers at lower elevations (less than 5000 metres) slowed at a faster rate than those at higher elevations.
| Glacier Zone | Glacier Velocity Change | | --- | --- | | Lower elevations (less than 5000 metres) | -16% | | Higher elevations (5000 metres and above) | -10% |
The slowdown was accompanied by glacier thinning, with average thinning at a rate of 0.22 metres per year from 2000 to 2005, accelerating to 0.57 metres per year from 2015 to 2020.
## A water crisis in the making
The thinning of glaciers has been reported across the Karakoram, Zanskar, and Hindu Kush Himalayan (HKH) ranges. A 2026 report by the International Centre for Integrated Mountain Development found that the HKH range experienced a 12% reduction in glacier area between 1990 and 2020.
Glacier retreat has a direct impact on water availability to the region, because of the water they store. All but one of the sub-basins supplying the Indus river system with water were found to have depleted glacier mass in a 2024 study.
Ladakh is a rain shadow area which is mostly dependent on the snow and glacier melt for water supply. The study's author, Tirthankar Ghosh, said that understanding the dynamics of how these ice bodies are flowing can help make better predictions of how they will evolve in the future.
The implications of the study's findings are clear: the glaciers in the Zanskar Himalayas are losing speed, and this has significant implications for water availability in the region. As the glaciers continue to thin and lose mass, the region's water supply will be at risk.
