plate tectonics Flashcards
crust
the outermost shell of a rocky planet.
mantle
layers of molten ricks between the crust and core
core
made up of mostly iron. separated into the outer core molten and inner core.
tectonic plate
the layers if rocks that make up the outer parts of the earths cutting the crust and upper mantle.
continental drift theory
the theory that contains gradually drifted over time their present position.
asthenosphere
a tin 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 rais to the top and the cooler denster parts silk.
convergent boundary
when two plates come together.
mountains
uplift of crustal plates that form eveated landmasses.
volcanoes
a vent or fissure in earths surface through which magma and gasses are expelled.
divergent boundary
when tectonics plates split apart.
transform boundary
when tectonic plates slide past each other.
fault
breaks in the crust the movement causes seimini waves earthquakes.
mid-ocean ridge
a long ridge of underwater volcanoes between two diverging oceanic plates.
subduction zone
a place where one tectonic plates sink under another and melts also forms a trench.
