Transcript for Drift Ice as a Geologic Agent, segment 06 of 11


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{{{Ice Wallow}}}

A particular seabed interaction related to the rhythmic movement of ice in a wave train is called ice wallow. The resulting bed forms called ice wallow relief are seen on the beach and shallow shore face of barrier islands. The action is similar to the pounding of a shipwreck in the surf zone which, in the process, is burying itself in the sand. However, the ice eventually melts and leaves a hole on the sea floor.

These Arctic summer time-lapse films are focused on small flows held against the shore face. Large and distant stationary flows at water depths of twenty meters or more are also wallowing on the seabed.

Densely spaced precision surveys off Reindeer Island documented numerous closed depressions fifty to one hundred meters in diameter and two to three meters in relief on a sandy bed. The surveys were done three years apart and exhibit remarkable changes. The track lines are dashed to show the survey control. Former depressions had been leveled while new ones had formed. In the production and filling of ice wallow relief sediment is moved laterally with a net current to the west.