A recent scientific study has shed light on a previously unobserved and potentially destabilizing phenomenon within the Greenland ice sheet: a massive outburst of water from a hidden subglacial lake that fractured and erupted through the ice surface. This event, which occurred in 2014, challenges long-held assumptions about how meltwater behaves beneath the vast ice sheet and has raised new concerns about its future stability and impact on global sea levels.
The research, based on satellite data, documents the explosive drainage of a subglacial lake in northern Greenland. Over a ten-day period, an estimated 90 billion liters of water surged upward with such force that it blasted a crater roughly two square kilometers wide and 85 meters deep into the ice. This finding is significant because scientists previously believed that meltwater primarily drained downward, flowing between the ice and the bedrock. The event, in a region where the ice was thought to be frozen to the ground, indicates that immense water pressure can force meltwater to move vertically, fracturing the ice from below.
The discovery has prompted a reevaluation of current models used to predict the ice sheet’s contribution to sea level rise. These models, which do not account for such dramatic, upward-flowing water events, may be underestimating the speed and scale of future ice loss. The incident also highlights a complex relationship between surface and basal water systems. The flood even caused a temporary but rapid slowdown of a downstream glacier, a clear sign of how these processes are interconnected.
As global temperatures continue to rise, the existence of such a powerful and destructive mechanism for meltwater drainage could have profound implications. Scientists are now working to better understand these hidden hydrological systems to more accurately forecast the rate at which the Greenland ice sheet will melt, a process that is a significant driver of global sea level rise.