Changes Within The Earth Geography 8

Geology Study of earth’s physical structure and history 4.6 billion years old Geologists: –Learn about changes –Understand why they occurred –Predict future changes

Inside the Earth Core: Center, hot metals –Inner core: Dense and solid –Outer core: Molten Mantle: 1,800 miles of rock –Mostly solid, upper layer is pliable –Magma pockets

Crust Thin Like frosting on a cake 5-6 miles thick under oceans miles thick under continents Uneven

Land and Water “Watery Planet” –Water covers 70% of surface –Salt water oceans 7 Continents Relief: differences in elevation between highest and lowest points

Landforms Mtns, hills, plateaus, plains, valleys, canyons, basins Shaped by internal forces –Volcanism –Movements that fold, lift, bend, break crust

Volcanos Magma breaks crust Lava: molten rock at surface Eruptions and lava flows create cone- shaped mountains Mt. Fuji

Changes in Earth’s Crust Fold: rock layers bend and buckle Fault: Break in crust Earthquake: sudden slip or movement Plate Tectonics: –Earth’s crust has a number of moving plates