plate tectnics Flashcards
crust
the outermost shell of a rocky planet
mantle
layer of molten rock between the crust and core
core
Made up of mostly iron. Separated into the outer core (molten) and inner core (solid)
Tectonic plate
The layer of rock that makes up the outer part if the Earth, including the crust and upper mantle
continental drift theory
continents gradually diffed over time
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 hotter parts of a gas or liquid rise to the top and the cooler parts sink.
convergent boundary
when two tectonic plate come together
mountains
uplift of crustal plates that form elevated landmasses
volcanoes
a vent or fissure in earths surface trough which magme 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 which produces earthquakes
mid-ocean-ridge
a long ridge of underwater volcanoes between two diverting oceanic plates
subduction zone
a place where one tectonic plate sinks under another and melts. Also forms a trench