Constructive and Destructive Forces.pdf

Why Are There Different Landforms? • The Earth’s physical landscape is partly the result of conflict between forces that build up the land (constructive forces) and those that wear down the land (destructive forces). Constructive Forces: • These are forces that push up the land to create mountains/h...

Why Are There Different Landforms? • The Earth’s physical landscape is partly the result of conflict between forces that build up the land (constructive forces) and those that wear down the land (destructive forces). Constructive Forces: • These are forces that push up the land to create mountains/highlands. This can occur in 3 ways: folding, faulting and volcanism. Deconstructive Forces: • These are forces that wear the land down via Constructive Forces: •These are forces that push up the land to create mountains/highlands. This can occur in 3 ways: folding, faulting and volcanism. 1) Folding – crustal plates move together forcing the land between to buckle and fold - This is the most common type of mountain ex. Rocky Mountains, Appalachians Constructive Forces: •These are forces that push up the land to create mountains/highlands. This can occur in 3 ways: folding, faulting and volcanism. 2) Faulting – parallel cracks in the crust allow the center portion of land to rise or fall, creating flat-topped mountains - least common type of mountain ex. Ottawa Valley, St. Lawrence Valley. Constructive Forces: •These are forces that push up the land to create mountains/highlands. This can occur in 3 ways: folding, faulting and volcanism. 3) Volcanism – cracks in the crust allow magma to reach the surface and cool and harden to become volcanic mountains - this type is the quickest to form ex. Hawaii, Canadian Shield, Coast Mountains Deconstructive Forces: •These are forces that wear the land down via erosion/ weathering. Weathering: this is the process of wearing away and breaking down the surface. This can be accomplished by chemical or mechanical processes. In average conditions, weathering is a slow process. But this rate can increase with a number of Deconstructive Forces: •These are forces that wear the land down via erosion/ weathering. A. Mechanical Weathering Mechanical weathering involves the disintegration of rock when it is split or broken into smaller pieces without it changing its composition. Examples of this would be abrasion, freezing-thawing, and Deconstructive Forces: •These are forces that wear the land down via erosion/ weathering. B. Chemical Weathering Chemical weathering involves the disintegration of rock when it is split or broken into smaller pieces by changing its composition. Examples of this would be hydrolysis or oxidation.