Theory question 307
Weathering, Erosion and Mass Movement(a) List: (i) three factors that influence weathering; (ii) two effects of landslides. (b) Describe the following processes of weathering: (i) exfoliation; (ii) frost action.
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(a)(i) Climate (temperature and rainfall); rock type and composition; rock structure (joints); relief; vegetation and organisms; human activities; time.
(ii) Loss of life and property; destruction of roads and farmland; blocking of rivers and flooding; deforestation; displacement of people.
(b)(i) Exfoliation: in deserts rocks heat strongly by day and cool at night; the outer layer expands and contracts more than the inside; stress causes cracks parallel to the surface; outer shells peel off like onion layers.
(ii) Frost action: water enters cracks in rock; at night it freezes and expands by about 10%; this pressure widens the cracks; repeated freezing and thawing breaks the rock into angular fragments (scree).
Describe the steps in order.