Meltwater Bursts Through Greenland Ice Cap

Typically, when glaciers in Greenland melt, the water drains into the underlying bedrock before eventually reaching the ocean. However, in 2014, a significant surge of meltwater from a subglacial lake erupted through the Greenland ice sheet’s surface, creating a crevasse 25 meters deep.

“This phenomenon is unprecedented,” remarks Malcolm McMillan, a researcher at Lancaster University, UK. “While we are aware of the subglacial lakes in Greenland, witnessing the destruction caused as water erupts from the ice sheet’s surface is entirely new to us.”

McMillan and his research team initiated their study upon observing a sudden 85-meter deep crater on the ice sheet, captured by satellite imagery in August 2014.

They found that within a span of 10 days in late July and early August 2014, these craters formed following a rapid drainage of the subglacial lake. About a kilometer downstream from the crater, the team identified significant ice turbulence, with water surfacing.

The researchers theorize that the pressure from the subglacial lake increased sufficiently to force the water up through fractures in the ice, ultimately leading to its explosive emergence from the ice sheet, which resulted in a considerable crevasse and an ice tower along its path.

According to McMillan, the meltwater was compelled to surface due to being encased by frozen ice in the bedrock. “It seems that when water flows into a frozen environment, it can accumulate enough pressure to trigger this unforeseen outcome,” he elaborates.

McMillan aims to utilize satellite imagery in future research to ascertain whether similar eruptions have occurred and if this phenomenon is a consequence of rapidly melting ice sheets in the context of rising global temperatures.

“This marks the initial exploration of a phenomenon that we were previously unaware of, and the upcoming challenge is to comprehend its implications and underlying mechanisms,” he concludes.