Tidal flat erosion by ice at La Pocatiere, Saint Lawrence Estuary

Abstract

Abstract The tidal flat areas of the Middle St. Lawrence Estuary are severely eroded by shore ice. Grooves parallel or perpendicular to the shoreline, measuring 30 to 80 cm wide, 20 to 35 cm deep, and 1500 to 2000 m long, and circular or subcircular basins up to 2 m in diameter and 20 to 40 cm deep are produced every spring by ice blocks that plough the surface and gradually disturb the sediments.