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. … The inner core is solid due to the pressure caused by the weight put on it by the Earth’s other three layers, the crust, the mantle, and the outer core.
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. Its outer boundary lies 2,890 km beneath Earth’s surface.
Seismic Waves
Seismic waves are waves that travel through or over Earth.
Oceanic Crust
the outermost layer of Earth’s lithosphere that is found under the oceans
Continental Crust
he layer of igneous, sedimentary, and metamorphic rocks that forms the geological continents
Density
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 describes one of the earliest ways geologists thought continents moved over time
Convergent Boundary
When two plates come together, it is known as a convergent boundary
Divergent Boundary
A divergent boundary occurs when two tectonic plates move away from each other
Transform Boundary
Transform boundaries are places where plates slide sideways past each other.
Sea-floor Spreading
Seafloor spreading is a geologic process in which tectonic plates—large slabs of Earth’s lithosphere—split apart from each other
