One of the largest glacial floods ever documented observed in Greenland

One of the largest glacial floods ever documented observed in Greenland
by Robert Schreiber
Berlin, Germany (SPX) Dec 16, 2024

For the first time, researchers have closely observed the catastrophic release of meltwater from a massive glacial lake in East Greenland, where 3,000 billion liters of water cascaded into the Scoresby Sound fjord in just a few weeks. The unprecedented event sheds light on the immense power of glacial meltwater and its potential hazards, offering critical insights into the phenomenon known as Glacial Lake Outburst Floods (GLOFs).

The event occurred when Catalina Lake, an immense reservoir dammed by the Edward Bailey Glacier, drained 3.4 cubic kilometers of water, equivalent to three times Denmark's annual water consumption. Scientists from the University of Copenhagen's Niels Bohr Institute monitored the flood in real time using satellite imagery - the first such observation despite the challenges of polar night and persistent cloud cover.

Niels Bohr Institute researcher Aslak Grinsted explained, "We have previously found traces of similar outburst floods, but this is the first time that researchers have been able to monitor an event and measure the water volumes in real time."

The mechanics of the outburst

Catalina Lake, located in a valley, had been accumulating meltwater for 20 years before the glacier-dammed lake reached its tipping point. Rising water eventually lifted the glacier, carving a massive 25-kilometer tunnel beneath the ice. This natural channel released the meltwater into the world's largest fjord, Scoresby Sound, between September 23 and October 11, during which the lake's water level dropped by 154 meters.

These GLOFs, caused by the sudden failure of ice or sediment dams, are becoming increasingly frequent as global temperatures rise due to climate change.

"The danger from glacier-dammed lakes is increasing due to global warming," said Grinsted. "It's vital to improve our understanding of this phenomenon to issue timely warnings should there be an imminent risk."

A global threat

While Greenland's sparse population spared the region from disaster, the event highlights the risks such floods pose in densely populated areas like the Himalayas, where similar floods have destroyed villages and claimed lives. A 2023 study estimated that 15 million people worldwide live under the threat of glacial lake outburst floods.

Looking ahead, Grinsted predicts that as Greenland's ice sheet continues to retreat, outbursts from even larger ice-dammed lakes will occur. He drew comparisons to the end of the last Ice Age, when the outburst of Lake Missoula released water volumes 2,500 times greater than the recent Catalina Lake event. "To understand these massive forces, we must study the largest outbursts when they occur," he emphasized.

Harnessing natural energy

The energy released by the Catalina Lake outburst was staggering. According to Grinsted, the force of the flood was comparable to the output of the world's largest nuclear power plant operating at full capacity for 22 days.

"In theory, the energy released from the Catalina Lake event could have continuously provided 50 megawatts of electricity, enough to meet the needs of a small town," Grinsted explained. However, Greenland's remoteness and lack of infrastructure present significant challenges for harnessing this power.

"If a brilliant engineer could figure out how to harness these meltwater outbursts, there's enormous power and energy potential in them," he concluded.

Research Report:Glacial lake outburst floods threaten millions globally