A new way of measuring how some glaciers melt below the surface of the water has uncovered a surprising realization: Some glaciers are melting a hundred times faster than scientists thought they were.

In a new study published today in Science, a team of oceanographers and glaciologists unpeeled a new layer of understanding of tidewater glaciers—glaciers that end in the ocean—and their dynamic processes.

“They’ve really discovered that the melt that’s happening is fairly dramatically different from some of the assumptions we’ve had,” says Twila Moon, a glaciologist at the National Snow and Ice Data Center at the University of Colorado-Boulder who was uninvolved with the study.

Some of this calving and glacial melt is a normal process that glaciers undergo