Glaciated Landscapes Flashcards
what was the time period for the Pleistocene
2 million- 11,500 years ago
How many years ago did the Quaternary period start
2.6 million years ago
what are the four types of cold environments
polar, alpine, periglacial, glaciers
what is the average annual temperature in a polar environment
-30 to -40 degrees
18,000 years ago was the last glacial maximum, what was its name
Denvensian
the last UK glacial advance was 12,000-10,000 years ago, what was its name
Lock Lomond Stadial
what period was the Little Ice Age
1550-1750
Eccentricity of the Earth’s orbit changes over a period of how many years
100,000
axial tilt of the Earth varies between which angles
21.8 - 24.4
the Earth wobbles on its axis over a period of how many years
21,000
what is the average size of an ice sheet
10,000 - 100,000 sq.km.
surging glaciers can flow up to what distance per day
100m
what % of all current glacier ice is contained in Antarctica
85%
the Greenland ice sheet consists of how much of the Earth’s total ice cover
11%
for every 100m in altitude, how much does the temperature decrease by
1 degree
what is roughly the average amount of precipitation that periglacial environments receive each year
600mm
how long do subsoil temperatures have to remain below 0 degrees, before they are considered permafrost
2 years
what % of the Earth experiences periglacial conditions
20%
how much % of land cover does sporadic permafrost cover
less than 50%
what is the range of height that pingos can reach
30-70m
what are the names of the two types of pingo
open system and closed system
ice-wedge polygons are usually found where
valley floors
what % of Canada is covered by some form of permafrost
over 50%
what % of Alaska is covered by permafrost
80%
