Download Geosphere PP

Dynamic earth: geosphere objec4ve Students will be able to describe the composi4on and structure of the Earth. Earth as a system Scien4sts divided this system into four parts: •  The Geosphere (rock) •  The Atmosphere (air) •  The Hydrosphere (water) •  The Biosphere (living things) GEOSPHERE: mostly solid, rocky part of the Earth; extends from the center of the core to the surface of the crust Discovering earth’s interior •  Scien4sts use seismic waves to learn about Earth’s interior (waves altered by the material it travels through) •  Measure changes in the speed and direc4on of seismic waves that penetrate the interior of the planet •  Learned that Earth is made up of different layers and have INFERRED what substances make up each layer Discovering earth’s interior: seismic waves Composi4on of the earth •  Scien4sts divide the Earth into layers: •  The crust •  The mantle •  The core (inner and outer) •  These layers are made up of progressively DENSER material toward the center of the Earth Composi4on of the earth CRUST = solid, outermost layer of the Earth •  thinnest layer •  makes up less than 1 percent of the planet’s mass •  5 km to 8 km thick beneath the oceans (thin) •  20 km to 70 km thick beneath the con4nents (thick) Composi4on of the earth Composi4on of the earth MANTLE = layer of rock between the Earth’s crust and core •  rocks of medium density •  64 percent of the mass of the Earth Composi4on of the earth CORE = central part of the Earth below the mantle; composed of the densest elements OUTER CORE = dense liquid layer INNER CORE= solid, dense; made up mostly of iron and nickel between 4,000°C to 5,000°C solid because it is under enormous pressure •  The inner and outer core make up about one-­‐third of Earth’s mass. Composi4on of the earth Composi4on of the earth The Earth can be divided into five layers based on the physical proper4es of each –  Lithosphere –  Asthenosphere –  Mesosphere –  Outer Core –  Inner Core Layers of the earth Lithosphere (litho = rock, sphere = layer) Solid, outer layer of the Earth that consists of the crust and the rigid upper part of the mantle. •  cool, rigid layer that is 15 km to 300 km thick •  divided into huge pieces called tectonic plates Layers of the Earth Asthenosphere (a = without, stheno = strength) Layer of the mantle beneath the lithosphere •  Weak and easily deformed •  made of mantle rock that flows slowly (allows tectonic plates to move on top of it) Layers of the earth Mesosphere (meso = middle) middle layer between outer core and asthenosphere –  Solid and strong •  Outer Core – dense liquid •  Inner Core – solid; dense, made up of mostly iron and nickel between 4,000°C to 5,000°C; solid because it is under enormous pressure