Planet Earth Test 1 Review PDF
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This document reviews key concepts in Earth science, including Earth's interior layers, chemical composition, and the continental drift hypothesis. It covers topics such as the crust, mantle, core, and the processes involved in the movement of continents.
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Class 3 -Earth’s interior layers: Chemical composition (Crust (Si+O)), (Mantle (Si, O, Mg, Fe)), (Core (Fe, Ni)) Iron(35%) Oxygen(30%) Silicon (15%) Magnesium(13%) Nickel (2.4%) Sulfur (1.9%) Calcium (1.1%) Aluminum (1.1%) Physical properties: Lithosphere (10-200km), Asthenosphere, mesosphere, outer...
Class 3 -Earth’s interior layers: Chemical composition (Crust (Si+O)), (Mantle (Si, O, Mg, Fe)), (Core (Fe, Ni)) Iron(35%) Oxygen(30%) Silicon (15%) Magnesium(13%) Nickel (2.4%) Sulfur (1.9%) Calcium (1.1%) Aluminum (1.1%) Physical properties: Lithosphere (10-200km), Asthenosphere, mesosphere, outer core, inner core -Earth’s Crust composition: O (46.3%) Si(28%) Al(8.1%) Middle Earth (mantle): (Fe+Si+O+Mg) Thickness~2,900 km, rock: peridotite -Continental crust: Composition (Si + O + Al), Granitic rocks, Thickness 40-70 km (oldest rocks on earth ~4.4 billion years), Thick/low density -Oceanic crust: Composition (Si + O +Fe + Mg), thickness (5-8 km), basaltic rocks, Thin/high density -The Moho: the boundary between the crust and mantle (mostly chemical) -The Guttenberg discontinuity: Boundary between mantle and core is sharp. Change in density across the core-mantle boundary is greater than at the earth’s surface -Lithosphere (10-200km): outermost layer rigid, solid, strong, and low temperature -Asthenosphere: Molten rocks, high temperature, weak, plastic, viscous, able to flow -Outer core: alloy of Fe+Ni, liquid, generates magnetic field -Inner core: alloy of Fe+Ni, solid Solar wind/flared of charger ions can damage satellites and other electric devices, earth’s magnetic field protects it from ions and solar radiation (mars and Venus have no magnetic field) Class 4/5 -Continental Drift Hypothesis (1960s-1990s): Alred Wegener (German meteorologist) all continents used to fit together, supercontinent Pangaea -Evidence for Continental Drift Hypothesis: 1. The fit of continents The shapes of N America, S America, Africa, and Europe. 2. The distribution of ancient climatic belts(past glacial deposits), 3. Fossil distribution: Fossils of land-dwelling organisms discovered in multiple continents, 4. Matching geologic units Rock units in Africa and S America match up, and Paleozoic mountain belts on either side of the Atlantic Ocean match up too (Failed to explain how his theory was rejected) -Pangea -Mantle convection: Arthur Holmes: Convection cells in the mantle as a mechanism for moving continents (occurs when a heated fluid expands and rises due to density differences), warned his ideas were purely speculative and had no scientific value until they acquire support from independent evidence -Mid-ocean ridge: Marie Tharp/Bruce Heezen -Bathymetry (depth of the ocean floor): first half-century scientists had no idea what the ocean bathymetry looked like, using echo sound a group of scientists in Columbia University began to map the ocean floor in the early 1950s -Echo sound: The travel time of the sound pulses indicates the seafloor's depth. -Mid-Atlantic ridge -Global heat flux -Seafloor spreading -Earth’s magnetic field -Liquid outer core -Magnetic polar wander -Magnetic reversals -Marine magnetic anomalies -Creation of new seafloor -Rifting – New Jersey/East African Rift - Age of Ocean Floor -Divergent Boundaries Class 6 -Convergent Boundaries -Transform/Strike-Slip -Active Margins -Passive Margins -Rate of Plate Movement -Subduction -Benioff Zone -Ocean-Ocean collision -Ocean-Continent Collision -Continent-Continent Collision -Continental Arc -Island Arc -Convection -Slab Pull -Ridge Push