Dynamic Earth Science Test

continental drift

the gradual movement of the continents across the earth's surface

convection currents

Circular currents in the mantle caused by the magma being heated by the core off the Earth

ocean trenches

deep sections of the ocean, usually where an oceanic plate is sinking below a continental plate

plate boundaries

the edges of tectonic plates

the 2 diff types of volcaonoes

stratovolcanoes and effusive

stratovolcanoes

cone-shaped with steep slopes, explode frequently

effusive volcanoes

volcanoes that have lowly viscous and low gas content magma

continental crust v. oceanic crust

Continental crust is less dense than oceanic crust

shield volcanoes

a broad, domed volcano with gently sloping sides, characteristic of the eruption of fluid, basaltic lava

mid-ocean ridge

underwater moutaine chain where new ocean floor is formed

How continents grow

magmatic addition and continental accretion

divergent boundary

plate boundary where two plates move away from each other

convergent boundary

plate boundary where two plates move toward each other

transform boundary

tectonic plate boundary where two plates slide past each other