Click on a feature below to see an example of that feature.

Arete: a steep-sided, sharp-edged bedrock ridge formed by two glaciers eroding away on opposite sides of the ridge.

Cirque: a semicircular or amphitheater-shaped bedrock feature created as glaciers scour back into the mountain. This is where the snow and ice forming the glacier first accumulates; it is the "headwaters" of a glacier.

Col: a low spot or pass along a cirque or an arete.

Groove: an elongate depression carved out of bedrock as numerous rock particles embedded in the base of a glacier scour away at the underlying bedrock as the ice flows across the landscape.

Hanging Valley: a valley eroded by a small tributary glacier, such that the elevation of the valley floor is higher than the elevation of the valley floor that the hanging valley joins. The erosive power of glaciers is dictated by their size: the larger a glacier, the farther down into the landscape it can erode. Thus the valley floors of small tributary glaciers will be higher in elevation that the valley floor of the larger glacier that the small tributary glacier joins.

Headwall: the steep back-wall of a cirque.

Horn: a pyramid-shaped mountain peak created by several glaciers eroding away at different sides of the same mountain.

Paternoster Lakes: a chain of lakes in a glacial valley.

Striations: lines etched in bedrock underlying glaciers as individual particles embedded in the glacier scratch the underlying bedrock. These lines indicate the orientation of glacial flow.

Tarn: a glacial lake produced by scouring. These are often found in cirques.

Truncated Spur: drainage divide that has been cut off as glaciers straighten the valleys they erode.

U-shaped Valley: a glacially eroded valley; also called a glacial trough.

Moraine: an accumulation of unconsolidated material deposited by glaciers. These accumulations tend to be unsorted; that is, we find many different sized particles deposited in moraines, ranging from fine silt to large boulders. The sediment and rock material in moraines also tend to have angular edges. There are many different types of moraines, and depending on the type, the appearance of moraines may vary.

End Moraine: an accumulation of unconsolidated material deposited at the snout end of a glacier. Two different types of end moraines are terminal moraines and recessional moraines. In alpine areas, these moraines tend to form as ridges, but the actual size of the ridges may vary considerably. These ridges extend across the valley that the glacier filled and may be curved slightly down-valley. The terminal moraine marks the farthest extent of glacial advance and thus is the end moraine located at the lowest elevation. Recessional moraines form as glaciers pause during periods of retreat, and thus are located at higher elevations than terminal moraines. After glaciers retreat, these end moraines may be altered or destroyed by subsequent fluvial erosion.

Ground Moraine: unconsolidated material deposited directly beneath the base of a glacier.

Lateral Moraine: unconsolidated material deposited along the sides of an alpine glacier. Lateral moraines may form on top of existing alpine glaciers along the sides of the valley walls. Freeze-thaw weathering results in debris falling on top of the glacial ice, forming a ridge. As glaciers melt, this material may be deposited on the landscape as a ridge.

Medial Moraine: moraine formed on top and in the middle of an existing glacier. When two alpine glaciers flow together, their lateral moraines join, forming a medial moraine, a ridge in the middle and on top of the glacier. As glaciers melt this material is deposited on the landscape but will most likely not be recognizable as material formerly part of a medial moraine.

Cirque Glacier: a small glacier occupying a cirque, but that does not extend down-valley from the cirque.

Valley Glacier: an alpine glacier flowing in a valley. In mountainous regions, glacial flow is restricted by the valley walls. These glaciers start in cirques and extend down-valley from the cirque.

Crevasses: cracks in the glacial ice. The upper 30 meters of glacial ice is somewhat brittle, and as the glacier flows, cracks develop. Crevasses rarely extend to depths below approximately 30 meters because the ice below that too plastic and the cracks close.

Ice Fall: the ice equivalent of a waterfall. As ice flows over a drop-off, it may break apart and then reform at the base of the drop-off.

Ogives: alternating bands of light and dark ice formed at the base of some ice falls. The bands bend down-glacier due to the higher flow velocity in the middle of the glacier than along the valley walls. The dark bands represent movement of ice over the ice fall in the summer when more melting occurs, while the light bands represent the movement of ice over the ice fall in the winter.