How are spillways formed?
The spillway is the most distinctive erosional landform formed by glacial-lake outbursts along the southern margin of the Laurentide Ice Sheet.
What is Englacial meltwater?
Englacial aquifers provide long-term storage of meltwater, potentially reducing the proportion of surface water reaching the bed. Thermal observations have also identified similar meltwater retention in the accumulation area in West Greenland (Humphrey et al., 2012).
What does a glacier leave behind?
Glaciers leave behind anything they pick up along the way, and sometimes this includes huge rocks. Called glacial erratics or erratic boulders, these rocks might seem a little out of place, which is true, because glaciers have literally moved them far away from their source before melting out from underneath them.
What are glacial channels?
A meltwater channel (or sometimes a glacial meltwater channel) is a channel cut into ice, bedrock or unconsolidated deposits by the flow of water derived from the melting of a glacier or ice-sheet. The channel may form on the surface of, within, beneath, along the margins of or downstream from the ice mass.
What is meant by a spillway?
spillway, passage for surplus water over or around a dam when the reservoir itself is full. Spillways are particularly important safety features for several types of dams.
What is service spillway?
Main spillways or service spillways They are masonry or concrete structure which functions for a designed flood in the rainy season. The main spillway can be constructed either within the body of a dam or at one end of it independently in a saddle in an away from the dam.
What causes basal slip?
basal slip: when a thin layer of water builds up at the ice-rock interface and the reduction in friction enables the ice to slide forward. enhanced basal creep: ice squeezes up against a large (>1m wide) bedrock obstacle the increase in pressure causes the ice to plastically deform around the feature.
What causes a glacier to move?
Glaciers move by a combination of (1) deformation of the ice itself and (2) motion at the glacier base. At the bottom of the glacier, ice can slide over bedrock or shear subglacial sediments.
What is meltwater geography?
Meltwater is water released by the melting of snow or ice, including glacial ice, tabular icebergs and ice shelves over oceans. Meltwater is often found in the ablation zone of glaciers, where the rate of snow cover is reducing.
What is ice river?
The river of ice is called a glacier.