U2 Plate Tectonics & Earths Layers

S6E5af GSE standards

Crust

the thin and solid outermost layer of the Earth above the mantle

Mantle

the layer of rock between the Earth's crust and core

Inner Core

A dense sphere of solid iron and nickel at the center of Earth

Outer Core

the liquid layer of the Earth's core that lies beneath the mantle and surrounds the inner core

Continental crust

The portion of the earth's crust that primarily contains granite, is less dense than oceanic crust, and is 20-50 km thick

Lithosphere

made up of the crust and the upper part of the mantle which is rigid and solid.

Oceanic Crust

The portion of Earth's crust that is usually below the oceans and not associated with continental areas, thinner and higher in density that continental crust and basaltic rather than granitic in composition.

Asthenosphere

the softer layer of the mantle on which the lithosphere (tectonic plates) move -made of solid rock that flows very slowly

Mesosphere

the strong, lower part of the mantle between the asthenosphere and the outer core -means middle

Tectonic Plates

pieces of the lithosphere that move around on top of the asthenosphere

Seismic Waves

waves produced by earthquakes, scientist use these waves to calculate the density and thickness of the layers of the Earth

Density

A property of matter representing the objects mass/volume

Convection Currents

A circulation pattern in which material is heated and rises in one area, then cools and sinks in another area, flowing in a continuous loop. This happens in the middle mantle of the Earth and causes the shifting of plates.

Alfred Wegner

Scientist who proposed the theory of continental drift

Pangea

term for the super continent which contained all the plates together

Continental Drift

Theory that the continents once formed a single landmass, broke up, and drifted to their present locations.

Plate Tectonics

The theory that explains how large pieces of the lithosphere, called plates, move and change shape.

Tectonic Plates

Pieces of the lithosphere that "float" on the asthenosphere.

Convergent Boundary

The type of boundary that forms when two tectonic plates collide.

Divergent Boundary

The type of boundary that forms when two tectonic plates divide

Transform Boundary

The type of boundary that forms when two tectonic plates slide past one another

Lithosphere

The rigid layer of the earth consisting of the crust and upper mantle.

Asthenosphere

Layer of earth right below the lithosphere. This is the layer on which the tectonic plates "float"

Folded Mountains

Formed when two tectonic plates collide and push earth upwards

Sea Floor Spreading

The process by which new oceanic lithosphere forms as magma rises toward the surface and solidifies

Subduction Zone

in tectonic plates, the site at which an oceanic plate is sliding under a continental plate.

Volcanic Mountains

Mountains that form when molten rock erupts onto the earth's surface

Evidence for Continental Drift Theory

fossils, continental fit, glacial evidence, continuous mountain ranges and rock layers

Convection Current

a current in the middle mantle caused by the rising of heated fluid and sinking of cooled fluid

Tectonic Plates