Earthquakes, Volcanoes & Plate Tectonics

Surface Waves Most destructive seismic waves

Composite Type of volcano; occur at convergent boundaries; may have multiple vents

Compression Force that occurs at convergent boundaries; reverse faults

Shear Forces along strike-slip faults

Geothermal Energy Created by the heat of magma; can be used to heat water creating steam that turns turbines and generates electricity.

Caldera Formed when the crater of a volcano collapses into the vent after an eruption.

Crater Steep-walled depression at the top of a volcano.

Kilauea Most active volcano on Earth

Primary Waves Fastest seismic waves

Tension Forces that occur at divergent plate boundaries; normal faults

Solar energy Energy from the sun

Fusion Process of creating nuclear energy by joining the nuclei of atoms

Hydroelectric Electrical energy created when water is used to turn turbines.

Fault Surfaces along which rocks break and move

Shield Type of volcano; non-explosive eruptions; occur at divergent boundaries

Tephra Lava that is blasted into the air by volcanic eruptions and solidifies as it falls to the ground as ash, cinders, etc.

Rift Valleys Forms in an area where two plates are pulling apart (divergent boundary)

Cinder Cone Type of volcano; single vent; can occur near the two other types of volcanoes.

Trenches Created at convergent boundaries at subduction zones where one plate dives beneath another.

Continental Drift Wegner’s hypothesis that all continents were once connected and slowly drifted to current positions.

Pangea Large ancient landmass composed of all the continents joined together.

Seafloor Spreading Hess’ theory that new seafloor is formed when magma is forced toward the surface at a mid-ocean ridge.

Plate Tectonics Theory that Earth’s crust and mantle are broken into plates that float and move around on a plasticlike layer of the mantle.

Divergent Boundaries Boundary where two plates are moving apart (divide).

Convergent Boundary Boundary where two plates are moving together.

Transform Boundary Where two plates slide past each other without converging or diverging; can create a strike-slip fault.