Two elderly men drowned Sunday when they were swept into the water while on a tour of Uummannaq on the western coast of Greenland. Sebastian H. Mernild of the University of Alaska said the phenomenon, known as jokulhlaup, occurs when lakes formed by glacial melt water burst through the ice, the Copenhagen Post reported Wednesday.

Mernild said jokulhlaup typically occurs where melted water has gathered on top of glaciers or glacial lakes have formed, which is likely to occur more often as temperatures in the Arctic rise. The floods can shatter bridges, roads and buildings in populated areas.