Glacial features Flashcards
what does a hanging valley look like?
flat bottom, water falls coming off them into the main u-shaped valley
how do hanging valleys form?
because there are higher valleys that have been left after the ice has melted, the streams that flow into them reach the main river by waterfall down the steep sides of the main valley. They are not cut down as much as the main valley because they don’t contain as much, therefore making them smaller
what does a ribbon lake look like?
long, narrow, found in valleys
how do ribbon lakes form?
because the glacier finds it difficult to erode the hard rock but can easily erode the soft rock forming a rock basin. The ribbon lake is dammed by a rock bar and moraine maybe deposited by the glacier which will also dam the lake
what does a truncated spur look like?
triangle faced, exposed pieces of cliff which have been eroded from their original size by a glacier
how do truncated spurs form?
the spurs from the original river have had their ends eroded off by the glacier so the interlocking spurs are now truncated spurs
what do u-shaped valleys look like?
they can be as large as 3 miles deep and 1 mile across, steep valleys, flat bottoms and misfit streams
how do u-shape valleys form?
as water moves down the slope it erodes everything in its path leaving a large u-shaped valley behind after the glacier has melted
what do pyramidal peaks look like?
a point pyramid shape, steep walls connecting to a point, made of jagged rocks from corries and arêtes
how do pyramidal peaks form?
when three corries are close together on a mountain, plucking and weathering on the back wall of each corrie reduces the mountain to a 3 sided slab/rock —> pyramidal peak
what do arêtes look like?
a thin wall, made of jagged and fragmented rock, often uncovered with a knife-edged ridge
how do arêtes form?
where two corries form close together on a mountain, plucking and freeze thaw weathering on the back wall of each corrie reduces the mountain to a narrow edge called an arête
