Plate Tectonics Flashcards
Crust
The outermost shell of a rocky planet.
Mantle
Layer of molten rock between the crust and core
Core
Made mostly of iron. separated into the outer core (molten) and inner core (solid)
Tectonic plate
The layer of rock that makes up the outer part of the Earth, including the crust and upper mantle. ( lithospheric plates)
Continental drift theory
The theory the continents gradually drifted over time to their present positions
Asthenosphere
A thin layer of Earth, about 150 miles thick, at the border between the mantle and the crust
Convection currant
The process in which the hotter parts of gas or liquid rise to the top and the cooler, denser parts sink.
Convergent boundary
when two tectonic plates come together
Mountains
Uplift of crustal plates that form elevated landmass
Volcanoes
A vent or fissure in Earthś surface through which magma and gasses are expelled
Divergent Boundary
When tectonic plates split apart
Transform boundary
When tectonic plates slide past each other.
Fault
Breaks in the crust. The movement causes seismic waves that produce earthquakes.
Mid-ocean ridge
A long ridge of underwater volcanoes between two diverging oceanic plates
Subduction zone
A place where one tectonic plate sinks under another and melts. also forms a trench