Presentation on theme: "Changing the earth’s relief Evolution of the landscape Textbook p. 314, 333-335."— Presentation transcript:
Changing the earth’s relief Evolution of the landscape Textbook p. 314, 333-335
Changing the earth’s relief: mountain formation Relief = shape of the earth surface Formation of mountains = Orogenesis through convergent tectonic plate movements mountain: - steep slopes - at least 600m high Mountains in the making: ➔ Himalaya, Rocky mountains, Alps
Laurentians Rocky Mountains Why are they different? ?
The three stages of Erosion Erosion 1.) Weathering 2.) Transport: water, wind, ice 3.) Deposition: in lake, stream, ocean
Changing the earth’s relief: Erosion Erosion is the gradual wearing away (destruction and /or removal) of land surface material, for example rock or soil. Three step process: – Weathering of rock (destruction of rock) – Transportation of soil and rock debris (through water, wind, glaciers). – Deposition of material at another location
Categories of Weathering / Erosion Mechanical Weathering – Composition of rock does not change – Through: - Variations in temperature and pressure example: freeze thaw cycle of water - Wind and water Chemical Weathering – Composition of rock changes – Through: - washing out of certain minerals enhanced through acid rain Biological Weathering – Living organisms release acids change + weaken the rock – Plant roots can break rocks.