Transform Boundary
A plate boundary where two plates move past each other in opposite directions
Convergent Boundary
A plate boundary where two plates move toward each other.
Divergent Boundary
A plate boundary where two plates move away from each other.
Plate Tectonics
A theory stating that the earth's surface is broken into plates that move.
Rifts
Grabens associated with divergent plate boundaries
Magma
A molten mixture of rock-forming substances, gases, and water from the mantle
Oceanic Crust
earths crust located under the ocean
Continental Crust
thick but lightweight layer of Earth's crust
Trenches
Deep, underwater Canyons.
Asthenosphere
The soft layer of the mantle on which the lithosphere floats.
Lithosphere
A rigid layer made up of the uppermost part of the mantle and the crust.
Mantle
The layer of hot, solid material between Earth's crust and core.
Convection Currents
the upward movement of warm air and the downward movement of cool air
Alfred Wegener
A German scientist who proposed the theory of continental drift
Volcano
A vent or fissure in the Earth's surface through which magma and gases are expelled
Earthquake
The shaking that results from the movement of rock beneath Earth's surface.
Faults
breaks in Earth's crust where rocks have slipped past each other
Stress
A force that acts on rock to change its shape or volume
Compression
Stress that squeezes rock until it folds or breaks
Tension
Stress that stretches rock so that it becomes thinner in the middle
Shearing
stress that pushes masses of rock in opposite directions, in a sideways movement
Subduction Zone
These boundaries mark the collision between two of the planet's tectonic plates.
Folding
the bending of rock layers due to stress