Eskers consist of outwash (stratified drift) deposited by subglacial streams flowing in ice caves formed by melting along the bed of a glacier. When the glacier melts completely, the subglacial stream deposit is left behind in the form of a sinuous ridge generally less than 100 feet in height. Eskers are often mined for the sand and gravel of which they are composed. Kames are small conical hills composed of stratified drift that are deposited in cavities formed beneath the ice by melting. Like eskers, thay are often mined for sand and gravel.
Drumlins are erosional landforms formed by the sculpting of the till that comprises the ground moraine beneath a moving glacier. They are streamlined with the direction of ice flow, and the upflow ends have steeper slopes than the downflow ends. A 3-D topographic map shows several drumlins aligned with a lower left to upper right flow direction.
The first image displays alpine glaciers located along the western margin of Prince William Sound in south central Alaska. Can you find the locations of the snow lines on any of the glaciers? The second image displays a 3-D topographic map of a terrain formed by alpine glaciers. Note the following:
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