Glacier lakes: Growing danger zones in the Himalayas
Fears rise of huge outburst flooding in the Himalayas as glaciers melt due to climate change.
Fears rise of huge outburst flooding in the Himalayas as glaciers melt due to climate change
It’s strangely calming to watch the Imja glacier lake grow, as chunks of ice part from black cliffs and fall into the grey-green lake below.
But the lake is a high-altitude disaster in the making – one of dozens of new danger zones emerging across the Himalayas because of glacier melt caused by climate change.
If the lake, situated at 5,100m in Nepal‘s Everest region, breaks through its walls of glacial debris, known as moraine, it could release a deluge of water, mud and rock up to 60 miles away. This would swamp homes and fields with a layer of rubble up to 15m thick, leading to the loss of the land for a generation. But the question is when, rather than if.
Mountain regions from the Andes to the Himalayas are warming faster than the global average under climate change. Ice turns to water; glaciers are slowly reduced to lakes.
When Sir Edmund Hillary made his successful expedition to the top of Everest in 1953, Imja did not exist. But it is now the fastest-growing of some 1,600 glacier lakes in Nepal, stretching down from the glacier for 1.5 miles and spawning three small ponds.
At its centre, the lake is about 600m wide, and according to government studies, up to 96.5m deep in some places. It is growing by 47m a year, nearly three times as fast as other glacier lake in Nepal.
“The expansion of Imja lake is not a casual one,” said Pravin Raj Maskey, a hydrologist with Nepal’s ministry of irrigation.
The extent of recent changes to Imja has taken glacier experts by surprise, including Teiji Watanabe, a geographer at Hokkaido University in Japan, who has carried out field research at the lake since the 1990s.
Watanabe returned to Imja in September, making the nine-day trek with 30 other scientists and engineers on a US-funded expedition led by the Mountain Institute. He said he did not expect such rapid changes to the moraine which is holding back the lake.
“We need action, and hopefully within five years,” Watanabe said. “I feel our time is shorter than what I thought before. Ten years might be too late.”
