Plate tectonics Flashcards
(16 cards)
.crust
the outermost shell of a rocky planet.
mantle
layer of molten rock between the crust and core.
core
made up of mostly iron. seperated into the outer core (molten metal) and inner core. (solid iron)
tectonic plate
the layer of rock that makes up the outer part of the earth, including the crust, and upper mantle.(lithospheric plates)
Continetal drift theory
The theory that the continents gradually drift 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 currents
The process in which the hotter parts of a gas or liquid rise to the top and the cooler, denser parts sink.
Convergent boundary
When two tectonic plates come together.
mountains
uplift of crystal plates that form elevated landmasses.
volcanoes
A vent or fissure in earth’s surface in which magma and gases are expelled.
transform boundary
When tectonic plates slide past each other.
Divergent boundaries
When tectonic plates split apart.
Fault
Breaks in the crust. The movement causes seismic waves which produces earthquakes.
Mid-ocean ridge
A long ridge of underwater volcanoes between two divergent oceanic plates.
Subduction zone
A place where one tectonic plate sinks under another and melts. Also forms a trench.
Rift valley
A long narrow valley between two diverging continental plates.
