EARTH LAYERS OF THE EARTH CRUST LITHOSPHERE OCEANIC

EARTH

LAYERS OF THE EARTH

CRUST (LITHOSPHERE) • OCEANIC PLATES • CONTINENTAL PLATES

CRUST(LITHOSPHERE) • OCEANIC - IS ABOUT 10 K THICK AND MADE UP OF ROCK WITH IRON AND MAGNESIUM CAUSED BY VOLCANIC ACTION. IT IS VERY DENSE • CONTINENTAL- IS ABOUT 30 -50 K THICK AND MADE OF IGNEOUS, METAMORPHIC, AND SEDIMENTARY ROCK. IT IS LESS DENSE.

PLATES TECTONICS • THERE ARE 12 PLATES. • CONVECTION CURRENTS IN THE MANTLE MOVE THE PLATES. • THE PLATES MOVE JUST A FEW INCHES EACH YEAR.

The plates move because of convection currents in the asthenosphere. http: //wc. pima. edu/~bfiero/tucsonecology/setting/images/convce lls 01. gif

ASTHENOSPHERE • • IT IS JUST BELOW THE CRUST. IT IS WEAKENED BY HEAT. IT IS WITHOUT STRENGTH. CONVECTION CURRENTS ALLOW THE PLATES ON TOP OF IT TO MOVE.

3 Types of Plate Boundaries: http: //geology. csupomona. edu/drjessey/class/Gsc 101/boundaries. gif

Great Rift Valley

Himalayan Mountains

Subduction Zones • http: //www. smarterscience. net/challengerd eep. html

UPPER MANTLE • IT IS 400 KM THICK • MADE OF ROCK RICH IN IRON AND MAGNESIUM. • IT IS MUCH DENSER THAN THE CRUST.

LOWER MANTLE • IT IS ABOUT 1900 KM THICK. • CONTAINS A GREATER AMOUNT OF IRON. • MAKES UP 41% OF THE EARTH’S MASS

OUTER CORE • IT IS MADE UP OF LIQUID METAL. • IT IS ABOUT 2100 KM THICK. • IT MAKES UP ABOUT 30% OF THE EARTH’S MASS.

INNER CORE MADE UP OF HARD METAL. IT IS ABOUT 1300 KM THICK. IT IS 2% OF THE EARTH’S TOTAL MASS.

EARTH’S INNER LAYERS • There are distinct layers to the earth’s interior. • Heavier elements tend to sink to the core • Lighter elements rise toward the surface • More is known about the crust than the mantle and core. • What we believe is true about the mantle and core comes from studying seismology.

SEISMOGRAPH • IT IS USED TO MEASURE THE MOTIONS OF THE GROUND.

Divergent Convergent (Subduction Zone) Convergent (Collision) • Seafloor Spreading • Mid-Ocean Ridge • Rift Zone • Red Sea • New Ocean floor • Trenches • Great Rift Valley • Mariana Trench • Volcanoes • Mt. St. Helens • Mountains • Andes Mountains Folded Mountains • Himalayas • Appalachian Mts • Rocky Mts Transform San Fault Andreas Fault

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