Glacier Landforms: Chatter Marks

Chatter marks are a series of often crescent-shaped gauges chipped out of the bedrock as a glacier drags rock fragments underneath it.

Photograph of chatter marksThese chatter marks from Greenland show the characteristic crescent-shaped marks caused when glacial ice drags rocks and debris underneath it. These chattermarks are about 15 centimeters (6 inches) across. —Credit: Mike Hughes

Photograph of chatter marksChatter marks and glacial striations are often found together, as seen on the Niagara Dolomite in the eastern Upper Peninsula, Michigan. —Credit: Ron Schott