Recent discoveries in Greenland are reshaping our understanding of massive flood events beneath ice sheets, offering compelling new perspectives on the formation of some Ice Age Floods-related features. Two recent studies highlight an unprecedented sub-glacial flood in 2014, where a staggering 90 billion liters of meltwater unexpectedly burst through nearly 91 meters (300 feet) of solid ice.
This previously undocumented phenomenon in Greenland involved a massive volume of water punching upwards, fracturing the surface, and creating a 2-square-kilometer (0.77 square-mile) crater 85 meters (279 feet) deep. Satellite data revealed that the ice surface dropped dramatically after having bulged from water pressure. Evidence downstream showed a heavily fractured area with large ice boulders and a scoured ice surface, indicative of immense erosive power.
This event challenges previous assumptions that the base of ice sheets is always frozen solid and provides critical insights into the destructive potential of sub-glacial meltwater. While the iconic Missoula Floods are well-established as a result of glacial lake outbursts, this Greenland discovery suggests that other, perhaps more localized or intermittent, sub-glacial flood breakouts could have played a significant role in shaping the landscape during past ice ages. Such events could explain certain geomorphological features that don’t neatly fit the Missoula Flood narrative, such as Moses Coulee and possibly much of the Upper Grand Coulee, opening new avenues for research into the diverse origins of Ice Age Floods-related landforms.
AI-condensed from articles in LiveScience by Ben Turner and ScienceAlert by Michelle Starr