In February, a chunk of glacier broke off in the Himalayas, causing a landslide that dammed a river. The dam burst, sending a torrent of water into the Dhauliganga River valley in Uttarakhand, India, destroying villages, bridges and two power plants. Over 200 people were killed.

The tragedy highlighted the dangers to human life of melting and shifting glaciers in the wake of climate change. And while the main circumstance of the Uttarakhand event, namely a landslide blocking a river, is statistically rare, other disasters involving glaciers are not uncommon and have taken thousands of lives globally.

When glaciers melt and recede, they leave behind hollows that puddle into lakes banked by debris and soft sediment, called glacial lakes. The banks are easily breached, causing floods. Over 1,300 floods and at least 12,000 deaths have been caused by the natural events in recent decades, according to a global assessment by the University of Leeds published in 2016 in Global and Planetary Change. The Himalaya, Karakoram and Kindukush mountain ranges in central Asia and the Andes in South America are the deadliest regions involving melting glaciers.

Continue reading this open access story in the July issue of The Nation’s Health.

Imja Tsho lake is located at the foot of the Imja Glacier in Nepal. The glacial lake, which is one of the fastest-growing in the Himalayas, threatens nearby communities with the potential for outburst flooding. Photo by Gagarych, courtesy iStockphoto