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
the region of the earth’s atmosphere above the stratosphere and below the thermosphere, between about 30 and 50 miles (50 and 80 km) in altitude.
inner core
The inner core is the fourth layer inside the Earth. It is a solid metallic ball made mainly of iron
outer core
Earth’s outer core is a fluid layer about 2,400 km thick and composed of mostly iron and nickel that lies above Earth’s solid inner core and below its mantle
seismic waves
Seismic waves are waves of energy that travel through Earth’s layers, and are a result of earthquakes,
oceanic crust
oceanic crust, the outermost layer of Earth’s lithosphere that is found under the oceans and formed at spreading centers on oceanic ridges, which occur at divergent plate boundaries
continental crust
continental crust, the outermost layer of Earth’s lithosphere that makes up the planet’s continents and continental shelves and is formed near subduction zones at plate boundaries between continental and oceanic tectonic plates
density
The density, of a substance is its mass per unit volume.
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
When two plates come together, it is known as a convergent boundary. The impact of the colliding plates can cause the edges of one or both plates to buckle up into a mountain ranges or one of the plates may bend down into a deep seafloor trench
divergent boundary
A divergent boundary occurs when two tectonic plates move away from each other.
transform boundary
A transform fault or transform boundary, sometimes called a strike-slip boundary, is a fault along a plate boundary where the motion is predominantly horizontal.
sea floor spreading
Seafloor spreading is a geologic process in which tectonic plates—large slabs of Earth’s lithosphere—split apart from each other. … The less-dense material rises, often forming a mountain or elevated area of the seafloor. Eventually, the crust cracks.
