Plate tectonics Flashcards
Lithosphere
the rigid outer part of the earth, consisting of the crust and upper mantle
Asthenosphere
the upper layer of the earth’s mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur
Mesosphere
a layer of Earth’s atmosphere
Inner Core
is a hot, dense ball of (mostly) iron
Outer Core
is mostly composed of liquid iron and nickel
Seismic Waves
an elastic wave in the earth produced by an earthquake or other means
Oceanic Crust
the outermost layer of Earth’s lithosphere that is found under the oceans and formed at spreading centres on oceanic ridges, which occur at divergent plate boundaries
Continental Crust
Continental crust is the layer of igneous, sedimentary, and metamorphic rocks
Density
Density is the substance’s mass per unit of volume. The symbol most often used for density is ρ, although the Latin letter D can also be used.
Alfred Wegener
Alfred Lothar Wegener was a German climatologist, geologist, geophysicist, meteorologist, and polar researcher.
Continental Drift
Continental drift is the hypothesis that the Earth’s continents have moved over geologic time relative to each other, thus appearing to have “drifted” across the ocean bed.
Convergent Boundary
A convergent boundary is an area on Earth where two or more lithospheric plates collide. One plate eventually slides beneath the other, a process known as subduction.
Divergent Boundary
occurs when two tectonic plates move away from each other
Transform Boundary
A transform fault or transform boundary, is a fault along a plate boundary where the motion is predominantly horizontal.
Sea-floor Spreading
a geologic process in which tectonic plates—large slabs of Earth’s lithosphere—split apart from each other
