Give one piece of evidence that supports Milankovitch's theory.
The regular occurrence of glacials, approximately every 100,000 years.
3 of 17
Explain what is meant by the climate feedback mechanism
Feedback effects are those that either amplify (positive) or diminish (negative) a change in climate (rates of warming or cooling). An example of positive would occur when a small increase in snow and ice cover increases albedo.
4 of 17
What is the term given to the short-term oscillations in climate within glacial and interglacial periods?
Stadials
5 of 17
When did the Little Ice Age occur?
Between 1500 and 1750
6 of 17
Outline the evidence for its occurrence.
Contemporary documents and paintings; abandonment of upland farms in Scandinavia and Iceland; advance of valley glaciers in Europe; southward extension of Arctic Sea ice sheet; rivers and lakes in UK freezing over in winter
7 of 17
Distinguish between an ice sheet and ice field.
An ice sheet is a gently sloping dome of thick ice that completely submerges the underlying topography. In contrast, an ice field is much smaller in extent and depth and does not completely bury the topography.
8 of 17
Distinguish between a valley glacier and a piedmont glacier.
A piedmont glacier is a valley glacier that extends beyond the end of a valley and spreads out over flatter and lower lying land.
9 of 17
Identify the 4 main factors affecting the global distribution of ice cover.
Latitude, altitude, relief and aspect
10 of 17
What percentage of the Earth's land area is covered by glaciers today?
10%
11 of 17
What was the approximate percentage at the height of the Pleistocene glaciation?
30%
12 of 17
Describe two ways in which the global distribution of ice cover in the late Pleistocene differed from that today.
Much more extensive (3 times overall), especially in North America and Europe; thicker (3000 to 4000 metres in North America and Europe).
13 of 17
Define permafrost.
Permanently frozen ground; soil and rock that remains frozen, even during the summer, at least for two consecutive years.
14 of 17
Define active layer.
The top layer of soil in permafrost environments that thaws during summer and freezes during winter.
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