glacial features on topographic maps
DESCRIPTION
Glacial features on topographic maps in relation to photographs and satellite imagesTRANSCRIPT
Glacial FeaturesCaitlin Spence, Hyun Kyung Park, Makoto
Dodo
U Shaped ValleyGlen Clova, Angus, Great Britain
A valley that forms when a glacier erodes a river val-ley from its original V shape to a U shape
Where photo-
graph was taken
Truncated spurs
U shaped valley
Misfit stream
Flat glacial trough; no con-
tour lines
Cirque (or Corrie)Llyn y Gadair, Gwynedd, Great Britain
A bowl-shaped depression carved out of a mountain by an alpine glacier
A steep-walled hollow, shaped like a half-bowl, formed by glaciation and frost wedgingCirques are found in mountainous regions populated with glaciers, or which have had a history of being glaciated
Cirque
Contour lines sug-gest height moun-
tains, where cirques are found
Ribbon LakeLong and narrow, finger-shaped lake, usually found in a glacial trough
Hanging ValleyA shallow glacial trough that leads into the side of a larger, main glacial trough
A valley most often formed as a result of glaciation, where a large glacier erodes a valley, at a perpendicu-lar angle to the hanging valley, to a deeper extent. The result is that of a small valley intersecting a larger val-ley at an elevation noticeably above the bottom of the larger valley. Hanging valleys can be, but are not al-ways, eroded by a glacier.
Lake carved out by large glacier
Hanging Val-ley
Hanging Valley animation
http://www3.interscience.wiley.com:8100/legacy/col-lege/strahler/0471238007/animations/ch20_animations/animation2.html
Stream leading to hanging valley
ArêteA sharp narrow ridge found in rugged mountains
A sharp-edged ridge of rock formed between adjacent cirque glaciers
An arête is a thin, almost knife-like, ridge of rock which is typically formed when two glaciers erode parallel U-shaped valleys. The arête is a thin ridge of rock that is left separating the two valleys.
GribGoch, Snowdia National Park in Gwynedd, Wales
Ribbon Lake
Cirque
Arête
Ribbon
Lake
Arête
CirqueTopographic Map of Crib Goch
HornA high mountain peak that forms when the walls of three or more glacial cirques intersect.
A pyramidal peak, or sometimes in its most extreme form called a glacial horn, is a mountaintop that has been modified by the action of ice during glaciation and frost weathering.
Mount Wilbur,Glacier National Park in Montana
Ribbon Lake
Glacial Horn
Cirque
Topographic map of Mount Wilbur
Ribbon Lake
Glacial Horn
Cirque
U-shape Valley?
MorainesGlacial moraine at Borrowdale, Lake District, Cumbria
Moraine : a French word that refers to any glacier-formed ac-cumulation .Terminal moraine : an accumulation at the outermost edge of where a glacier or ice sheet existed. Recessional moraine: moraine located "behind" the outermost edge of a glacier, formed when the glacier lingers in one spot for a long time. Ground moraine: gently rolling hills and plains deposited by ice. Lateral moraine: ridges of till on the sides of a glacier. Medial moraine: a moraine formed when two glaciers merge (a tributary and trunk glacier) and their lateral moraines come to-gether to form a single moraine. Push moraine: a moraine created by till that was a moraine de-posited by an earlier glacier that once covered the area. Ablation moraine: a moraine formed from material that fell upon the glacier.
Moraine
This ridge along the edge of a field is evidence that this area was covered by ice about 10,000 years ago. It was not constructed, but was left at the front of a melting glacier, as with melting glaciers in Canada or Norway to-day.
As glaciers move, they scrape along the valley floor, erod-ing large amounts of rock material. They also transport frost-shattered boulders that fall from the valley sides and land on the glacier. When the glacier melts, this mixture of finely-ground rock, pebbles, and large boulders – moraine – is left as ridges both at the glacier “snout” (terminal moraine) and along the valley sides (lateral moraine).