Unit 46 Review Questions

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. Permafrost:

is common in both the Northern and Southern Hemispheres correct incorrect

is primarily discontinuous north of the Arctic Circle correct incorrect

is not currently present in Alaska correct incorrect

extends further south during periods of extensive glaciation correct incorrect

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. Why are wet soils common in periglacial landscapes?

Water moves upward from deep underground aquifers. correct incorrect

There is often limited drainage. correct incorrect

Heavy rainfall is common in summer months. correct incorrect

They are subject to substantial runoff from melting snow from higher elevations. correct incorrect

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. In what permafrost layer would you expect to find the most rocks broken down by frost wedging?

Active layer correct incorrect

Upper reaches of the permafrost table correct incorrect

Lower reaches of the permafrost table correct incorrect

Permanently frozen ground at extensive depths correct incorrect

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. The patterned ground found in periglacial environments:

requires permafrost for its formation correct incorrect

is the remnant of melted ice wedges correct incorrect

is an extensive pattern of interconnected polygons correct incorrect

results from frost-shattered rock, frost upheaving, and gravity correct incorrect

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. Polygon shapes just like those seen in ice-wedge polygons at far northern latitudes are currently evident in the Midwest region of the United States. This means:

there are extensive regions of permafrost underlying these Midwest areas correct incorrect

there once were regions of permafrost underlying these Midwest areas correct incorrect

continental glaciers did not reach the Midwest correct incorrect

the Midwest polygon shapes must have originated through some other mechanism than ice wedging correct incorrect