crust

Earth's thin outer skin

mantle

very thick layer of Earth under the crust

core

layer beneath the mantle; has an outer and inner part

lithosphere

asthenosphere

part of the mantle; rock is melted and taffy-like

weathering

erosion

removal and transportation of weathered material

deposition

dropping or settling of eroded material

glaciers

huge sheets of ice

uplift

land rising back up after a glacier retreats

meteorites

rocks from space

plate tectonics

mid-ocean ridge

chain of mountains that runs  through the world's oceans

rift

deep valley where plates of the Earth move apart

sea-floor spreading

divergent boundary

place where 2 or more plates are moving away from each other 

convergent boundary

place where 2 tectonic plates push into each other

transform fault boundary

2 plates move past each other in opposite directions

Pangea

name of the supercontinent that was formed from all of the continents

fault

break in the Earth's crust where rocks can slide past each other

earthquake

snap and slide of rocks as energy is released in Earth's crust

focus

point inside Earth where an earthquake begins

epicenter

point on the Earth's surface directly above the focus of an earthquake

P waves

fastest waves caused by earthquakes;

primary waves

S waves

second-fastest waves caused by an earthquake;

secondary waves

seismograph

instrument that detects earthquake waves

Richter scale

uses the size of waves recorded on a seismograph to determine how strong an earthquake is

tsunami

large wave that forms in the ocean as the result of an earthquake

volcanoes

mountain formed when magma is pushed to the Earth's surface and builds up

shield volcano

composite volcano

formed by a mixture of explosive and nonexplosive eruptions

cinder cone volcano

formed by explosive eruptions; often erode quickly; have steep sides