What is a glacial landform?
A glacial landform is a landform created by the action of glaciers. Most of today's glacial landforms were created by the movement of large ice sheets during the Quaternary glaciations.
Questions about Glacial landform
Short answers, pulled from the story.
What is the difference between erosional and depositional glacial landforms?
Erosional glacial landforms are carved when expanding glaciers crush, abrade, and scour rock and bedrock, producing features such as striations, cirques, arêtes, horns, and U-shaped valleys. Depositional glacial landforms are built when retreating glaciers leave behind crushed rock and sand, producing features such as moraines, eskers, and kames.
How do striations show the direction a glacier moved?
Striations are grooves and indentations in rock outcrops formed when small sediments on the bottom of a glacier scrape across the Earth's surface. The direction of the striations shows the direction the glacier was moving.
What is the difference between glacial till and fluvioglacial deposits?
Glacial till is composed of unsorted sediments eroded, carried, and deposited directly by the glacier. Fluvioglacial deposits were deposited by meltwater rather than the glacier itself, so their sediments are more size sorted than glacial till.
How do kettle lakes and moraine-dammed lakes form?
Kettle lakes form when a retreating glacier leaves behind a chunk of ice that later melts to create a water-filled depression. Moraine-dammed lakes form when glacial debris dams a stream or snow runoff, as with Jackson Lake and Jenny Lake in Grand Teton National Park.
Why is the glacial origin of some landforms disputed?
Erling Lindström has argued that roches moutonnées may have had most of their shape before glaciation, since their jointing predates glaciation and similar forms appear in tropical areas. The glacial buzzsaw effect has been rejected by various scholars, and the Gulf of Bothnia and Hudson Bay are known to be more the result of tectonics than of glacial erosion.