Earth Science Quiz #20

Crust

Thin brittle outer layer of earth composed of silicate rich rocks

Mantle

Located beneath the crust is the thickest internal layer composed of heavy iron and magnesium silicate rocks

Outer Core

A thick layer of molten iron and nickel

Inner Core

A solid sphere of iron and nickel in the other core

Alfred Wegener

A German meteorologist that proposed the theory of continental drift in 1912

Continental Drift

The continents were able to move about earth’s surface

Pangaea

The name given by Wegner for the most recent assemblage of all the land masses to form one supercontinent

Plate Tectonics

The concept of tectonic plates shifting due to convective forces in the mantle

Lithospheric “Plate”

segments of the mantle that contains the crust and the mantle

Lithosphere

Layer consisting of the crust and uppermost mantle

Continental Crust

Lower density thicker and granitic in composition

Oceanic Crust

high density thin and basaltic in composition

Moho

Boundary between the crust and the uppermost mantle. Identified by the rapid increase of wave speed between the two layers

Astenosphere

Slow flowing viscus semi solid layer. Large convection currents occur here.

Mesosphere

Lowest part of the mantle that behaves like a solid and is composed of iron and magnesium rich silicate rocks

Earthquake

Any sudden release of energy that causes a shaking in the ground

Common causes of earthquakes

Volcanic eruption, meteorites, landslides

Focus

point beneath the earth’s surface where the motion occured that generated the earthquake

Epicenter

Point vertically above the focus at earth’s surface.

Body Waves

Seismic Waves that travel through the earth’s interior

Surface Waves

waves that travel along earth’s surface