Athabasca - Far Flashcards
Where is the Athabasca glacier located?
The Columbia Icefield - North America.
325km squared, through the Banff and Jasper national parks.
Feeds 8 major glaciers.
Describe the push moraines of the Athabasca glacier.
Located in the front of the glacier (seasonal push moraines).
2 - 20m apart and are 0.7 - 2m high
Produced by seasonal shift of the snout where retreat and dumping of debris happens in the summer, followed by movement in the winter.
This causes material to be left in ridges as the glacier retreats next summer.
Used to track glacial retreat.
Describe the recessional moraines of the Athabasca glacier.
Marks stationary periods of the glacier during retreat, ranges between 3 - 6m high.
Furthest has been dated at 1870 but has also been seen at 1938, 1950, and 1960.
Used to study how plants have colonised fresh glacial debris.
Describe the lateral moraines of the Athabasca glacier.
Along the southeast side of the glacier is a 1.5km long lateral moraine, 124m high.
From high input of debris from slopes above being composed mainly of limestone which is weathered easily from freeze-thaw.
The accumulation of debris along the side of the glacier prevents ice beneath from melting as rapidly as the rest of the glacier.
Over time the lateral moraine will lower as the ice melts.
Describe the pro-glacial lake, Sunwapta, in the Athabasca glacier.
Between the snout and the last recessional moraine, from meltwater build up.
Progressively lowered by meltwater erosion, eventually the lake will disappear.
