Greenland ice sheet shattered by hidden lake flood

A massive iceberg flood in northern Greenland shook nearly 85 meters of ice, rushing to the ground in a rare and violent incident, reshaping the landscape.

The outbreak was triggered by a sudden drainage of a hidden lake beneath the ice sheet, fractured and twisted a 54 football field of size, spreading 25 meters of ice and searching for a bunch of clean, naked ice, almost twice as many as Central Park. This dramatic discovery in a new Natural Earth Science Research reveals an unrecognized form of glacier collapse that could change future predictions for sea level rise.

Floods from below: Hidden Threats

The event took place in the summer of 2014, but was only recently identified by the international team led by Lancaster University. Researchers tracked a sudden appearance of 2 kilometers using high-resolution satellite data and digital elevation models² The crater on the surface of the borneol is 90 million cubic meters of water (equal to 9 hours of Niagara River, peak flow drops at peak flow – draining from a previously unknown sub-icy lake.

Shocked scientists are where the water goes next. Instead of flowing under the glaciers as the model suggests, it surges upwards, destroying the surface of the ice.

“When we first saw this, because it was so unexpected, we thought there was a problem with the data,” said lead author Dr. Jade Bowling. “But as we delved into the analysis, it was clear that what we were observing was the consequence of a large amount of water that escaped from under the ice.”

Surface eruptions are different from anything seen before

The group found a large pile of cracked and disturbed ice about a kilometer downstream of the collapsed site, measuring 385,000 square meters. The surface was broken into jagged ridges and huge raised blocks – clear evidence that strong water erupted from below.

• Floods run out in just 10 days in July 2014
• The collapsed basin is 85 meters deep, forming more than 2 square kilometers.
• The outbreak searched for 6 square kilometers of ice surface
• Satellite images show features of lakes that have existed since at least 1985
• Similar drainage in 1990 also did not damage the surface, making the 2014 event unique

Rethinking how to drain the ice sheet

So far, the fusion flow under Greenland ice sheets has been considered a one-way path from the surface to bedrock, then at sea. This discovery flips the model. The team proposed that under great pressure, the water would break the frozen base ice and then return to the surface. Their modeling shows that the bed is cold, which was previously thought to be such an event.

“It has taught us new and unexpected things about the way ice sheets are extremely invested in surface melting,” said Dr. Amber Leeson. “And highlighted the need for a better understanding of the complex hydrological systems of ice sheets now and in the future.”

What’s more interesting is that the impact of the flood did not stop. The influx of water could reenter the glacier system further, which could be a large calving event at the end of the glacier and triggered a 63% drop in seasonal ice velocity.

Impact on the Warming Arctic

This discovery raises the urgent question: Will more such floods occur as warming accelerate ground melts? Is today’s model lacking a key form of glacial vulnerability? According to co-author Professor Mal McMillan:

“Satellites are an important tool to monitor the impact of climate change and provide critical information to build realistic models of how our planet will change in the future.”

Since 68% of the ice beds in Greenland are expected to be frozen or thermally uncertain, the likelihood of eruption may increase as more surface melt penetrates into areas of this knowledge. Researchers call for a focus on the ice sheet’s underpan pipeline to better predict its future behavior.

The study is a collaboration between 15 institutions and is funded by the UK Natural Environment Research Council, the European Space Agency, and the UK Research and Innovation.

Journal Reference

Bowling JS, McMillan M, Leeson AA, etc. “Floods under the iceberg erupted from the surface of Greenland ice sheet.” Natural Earth Science (2025). doi: 10.1038/s41561-025-01746-9

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