A new scientific study has raised serious concerns about the growing danger posed by unstable hanging glaciers in the Central Himalaya, warning that these fragile ice masses could trigger devastating avalanches and downstream disasters in Uttarakhand’s Alaknanda basin.
The research highlights an urgent need for monitoring and risk management as climate change and rapid development increase human exposure in one of India’s most ecologically sensitive and geologically fragile regions.
The study, conducted by researchers from the Indian Institute of Science, Indian Institute of Technology Bhubaneswar, and the Defence Research and Development Organisation, identified 219 hanging glaciers across the Alaknanda basin in Uttarakhand. These glaciers, which cling to steep mountain slopes and often end abruptly, cover an area of around 72 square kilometres and contain an estimated ice volume of 2.39 cubic kilometres.
Hanging glaciers are particularly dangerous because they are inherently unstable. Unlike larger valley glaciers, they are perched on steep terrain and are prone to sudden break-offs. The study found that nearly one-third of these glaciers are already in a highly unstable condition, making them vulnerable to collapse.
Researchers explain that climate change is a key driver of this instability. The Himalaya has been warming faster than the global average over the past two decades, leading to accelerated glacier retreat. As glaciers shrink, they lose structural support, causing parts of the ice mass to detach. This process often results in avalanches of snow and ice, which can travel rapidly down mountain slopes.
While such events are a natural part of glacier dynamics, they become hazardous when they occur near human settlements, roads, or infrastructure. The Alaknanda basin, a crucial headstream region of the Ganga River, has seen a sharp rise in development in recent years. The region includes important pilgrimage sites such as Badrinath Temple and Kedarnath Temple, along with expanding towns, highways, and hydropower projects.
Using satellite imagery, elevation data, and avalanche simulations, the researchers assessed how far potential ice avalanches could travel. Their findings indicate that in a worst-case scenario, avalanches could reach major settlements such as Mana, Badrinath, and Hanuman Chatti.
The simulations also revealed that avalanche debris could reach heights of over 50 metres in some areas, with even greater intensity in upstream zones. Such events could bury infrastructure, block rivers, and create temporary lakes. If these lakes burst, they could trigger catastrophic floods downstream, compounding the disaster.
The study draws attention to past incidents that demonstrate the real-world risks of glacier-related hazards. The Chamoli disaster is one such example, where a glacier collapse led to a massive debris flow, causing widespread destruction and loss of life.
One of the most alarming findings of the study is the rapid increase in human exposure in high-risk zones. Built-up areas in vulnerable regions have expanded dramatically, from around 8,000 square metres in 2000 to a projected 150,000 square metres by 2030. During the same period, the population in these areas is expected to rise from fewer than 400 people to more than 8,500.
The stretch between Badrinath and Mana has seen particularly rapid growth, with infrastructure and settlements expanding closer to steep glacier slopes. Key routes such as National Highway 7, which is vital for connectivity and pilgrimage, pass through areas identified as potential avalanche paths.
However, the study also notes that not all hanging glaciers pose the same level of threat. Some are located above larger glaciers and are less likely to directly impact populated areas. Others, however, hang directly above valleys and settlements, where even a moderate collapse could have severe consequences.
Despite the risks, large-scale monitoring of hanging glaciers in the Himalaya remains limited. In contrast, similar glaciers in the European Alps are closely monitored using advanced technologies such as radar systems, time-lapse cameras, and early warning mechanisms.
The researchers argue that implementing targeted monitoring systems in high-risk Himalayan regions could significantly reduce future disaster risks. While it may not be feasible to monitor every glacier, identifying the most dangerous ones and focusing resources on them would be a practical and effective approach.
The findings underscore the urgent need for integrating scientific research into planning and development decisions in mountain regions. As climate change continues to destabilise glaciers and human activity expands into vulnerable zones, the risk of cascading disasters is increasing.
Experts warn that without timely intervention, unstable hanging glaciers could pose a growing threat to lives, infrastructure, and critical water systems in the Himalaya, making it essential for authorities to act before a major disaster strikes.