How many end moraines can a glacier have?
There are two types of end moraines: terminal and recessional. Terminal moraines mark the maximum advance of the glacier.
What is the difference between an end moraine and a ground moraine?
An end moraine is a ridge of till that forms at the terminus of a glacier when the glacial budget is at equilibrium. A ground moraine is a layer of till that is deposited as ice melts when glacial ablation exceeds accumulation.
What causes end moraine?
Dump moraines occur when rock, sediment, and debris, which accumulate at the top surface of the glacier, either slide, fall, or flow off of the snout of the glacier. As temperatures increase, glaciers begin to retreat faster, causing more glacial till to be deposited in the form of terminal moraines.
What are the 3 different types glacial moraines?
There are many different types of moraines that form as a glacier carves its way across a landscape: lateral moraines, which form on the side of the glacier; supraglacial moraines, which form on top of the glacier; medial moraines, which form in the middle of the glacier; and terminal moraines, which form at the end of …
Where do you find the most debris on a glacier?
These long, dark bands of debris are visible on top and along the edges of glaciers. Medial moraines run down the middle of a glacier, lateral moraines along the sides, and terminal moraines are found at the terminus, or snout, of a glacier.
How can you tell if a valley is formed by a glacier?
They have a characteristic U shape in cross-section, with steep, straight sides and a flat or rounded bottom (by contrast, valleys carved by rivers tend to be V-shaped in cross-section). Glaciated valleys are formed when a glacier travels across and down a slope, carving the valley by the action of scouring.
What do glaciers leave behind?
When glaciers retreat, they often deposit large mounds of till: gravel, small rocks, sand, and mud. Glaciers do not always leave moraines behind, however, because sometimes the glacier’s own meltwater washes the material away. Streams flowing from glaciers often carry some of the rock and soil debris out with them.
What is the end of a valley called?
The head of the valley or, less commonly, the valley head, refers to the uppermost part of a valley.
What is the difference between alpine and continental glaciers?
Continental glaciers form in a central location with ice moving outward in all directions. Alpine glaciers form in high mountains and travel through valleys. Ice caps cover large areas. Because glaciers move, they have characteristic features like crevasses and bergshrunds.
What is another name for a continental glacier?
Continental glaciers are continuous masses of ice that are much larger than alpine glaciers. Small continental glaciers are called ice fields. Big continental glaciers are called ice sheets. Greenland and Antarctica are almost entirely covered with ice sheets that are up to 3500 m (11 500 ft) thick.
What are two main types of glaciers?
There are two main types of glaciers: continental glaciers and alpine glaciers.
Does cirque mean circus?
A cirque (French: [siʁk]; from the Latin word circus) is an amphitheatre-like valley formed by glacial erosion.
Is cirque erosion or deposition?
Valley glaciers form several unique features through erosion, including cirques, arêtes, and horns. Glaciers deposit their sediment when they melt. Landforms deposited by glaciers include drumlins, kettle lakes, and eskers.
What does a cirque glacier look like?
Cirques are bowl-shaped, amphitheater-like depressions that glaciers carve into mountains and valley sidewalls at high elevations. Often, the glaciers flow up and over the lip of the cirque as gravity drives them downslope. Lakes (called tarns) often occupy these depressions once the glaciers retreat.
Where is ice thickest in a glacier?
Continental glaciers do not flow “downhill” because the large areas that they cover are generally flat. Instead, ice flows from the region where it is thickest toward the edges where it is thinner, as shown in Figure 16.9.