What are glacial flows?
Glaciers flow downslope because they accumulate mass (ice) in their upper portions (from precipitation and from wind-blown snow) and ablate (melt, sublimate and calve ice bergs) in their lower portions. Glaciers always flow downslope under the weight of their own gravity.
How do glaciers deform as they flow?
Glaciers move by internal deformation of the ice, and by sliding over the rocks and sediments at the base. Internal deformation occurs when the weight and mass of a glacier causes it to spread out due to gravity. Sliding occurs when the glacier slides on a thin layer of water at the bottom of the glacier.
What does it mean when a glacier is advancing?
Glaciers lose ice mass every year, to melting and sublimation. As a result, the glacier grows, extending farther down the valley than it did previously. This is called an advance. When glaciers melt faster than they are replenished by precipitation, the total volume decreases. The glacier shrinks.
Which part of a glacier moves the fastest?
The flowing ice in the middle of the glacier moves faster than the base, which grinds slowly along its rocky bed. The different speeds at which the glacier moves causes tension to build within the brittle, upper part of the ice.
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. This means a glacier can flow up hills beneath the ice as long as the ice surface is still sloping downward.
What happens to snowflakes as they become progressively buried?
they begin to melt as they are insulated from the cold airC. they become interlocking crystals of iceD. they can become brighter white because of trapped airE.
In what direction does a spit typically grow with time?
in the same direction as a longshore currentC. in the direction from which waves are approaching the coastD.
What is probably the least expensive approach for avoiding shoreline hazards?
What is probably the least expensive approach for avoiding shoreline hazards? Forbid the building of houses or other structures in high risk areas.
Which of the following parts of a shoreline is more likely to experience intense erosion?
Which of the following parts of a shoreline is more likely to experience intense erosion? The seaward end of a promontory.
What happens on either side of the equilibrium line in a glacier?
melting occurs only above the line and sublimation occurs only below the lineC. above the equilibrium line, the amount of accumulation exceeds the amount lost by various processesD. air temperatures are below freezing below the line and above freezing above the line…
Why are the margins of glaciers darker than the middle?
The margins of glaciers are usually darker than the interior primarily because growth and associated glacial erosion. When glacial accumulation is greater than glacial ablation, the result is glacial. retreat and associated glacial deposition.
What happens if there is more melting than snowfall?
A glacier is a pile of snow and ice. In cold regions (either towards the poles or at high altitudes), more snow falls (accumulates) than melts (ablates) in the summer season. If the snowpack starts to remain over the summer months, it will gradually build up into a glacier over a period of years.