80 likes | 446 Views
Forces Shaping the Earth. Chapter 1, Section 3. Inside the Earth. Scientist can only study the top layer of the earth – crust. - dev. a picture of the earths inside. Core – center of Earth - mostly iron mixed w/ other metals (liquid) Mantle – surrounds core
E N D
Forces Shaping the Earth Chapter 1, Section 3
Inside the Earth Scientist can only study the top layer of the earth – crust. - dev. a picture of the earths inside. Core – center of Earth - mostly iron mixed w/ other metals (liquid) Mantle – surrounds core - 2 parts: inner mantle is solid surrounding core. - outer mantle is liquid molten rock (magma).
Cont. Crust – uppermost layer of earth - reaches 31 to 62 miles deep, including ocean floors - thicker below the continents. Continents- massive land areas (7)
Forces beneath Earth’s crust Plate Tectonics – theory, states that crust consists of plates that move. - float on liquid rock - move in different directions Pangaea – all continents were connected as an original land mass. (theory) Pacific ocean plate moves 4 inches per year.
When plates meet Plates pull away from each other and collide with each other. - collisions produce mountains (Himalayas) - plates sliding against each other produce earthquakes (violent mvmt. of earths crust) Tsunamis – huge waves caused by undersea earthquakes. ( up to 100 ft.) Faults – caused by plates sliding against each other - huge cracks in the ground San Andreas Fault (Cali)
Forces Shaping Landforms Weathering – process of breaking surface rock into boulders, gravel, sand, and soil. Process: water seeps into cracks of rocks, freezes, and breaks the rocks. - also caused by chemicals and seeds Erosion – process of wearing away or moving weathered material
Cont. Water, wind, and ice are the greatest factors in erosion. - wind moves sand - water in streams moves sand Areas that receive the sand benefit. Glaciers – Giant, slow moving sheets of ice - cause erosion - can move rocks, boulders - can carve valleys