plate tectonics Flashcards
crust
The outermost shell of a rocky planet
Mantle
layer of molten rock between the crust and core
core
Made up mostly of Iron. Separated into the outer core (molten) and inner core (solid)
Tectonic plate
The layer of the rock that makes up the outer part of the earth including the crust and upper mantle (lithosphere plates)
Continental drift theory
The theory that continents that continue gradually drifted over time to their present position(floated away)
asthenosphere
A thin layer of earth about 150 miles thick at the border between the mantle and the crust
convection current
The process in which the hottest part of a gas or liquid rise to the top and the cooler denser parts sink at the bottom
Convergent boundary
when two tectonic plates come together
Mountains
uplift of crustal plats that form elevated landmases
volcanoes
a vent or fissure in earth surface through which magma and gases are expelled
divergent boundary
when tectonic plated split a part
transform boundary
when tectonic plates slide past each other
fault
breaks in the crust the movement cause seismic waves which produce earthquakes
mid ocean ridge
a long ridge of underwater volcanos between two diverging oceanic plates.
Subduction zone
A place where one tectonic plate sinks under another and melts. Also forms a trench