plate tectonics 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 make up the outer part of the Earth ,including the crust and the upper mantle lithospheric plate
continental drift theory
the theory that continents gradually drifted over time to their present position
asthenosphere
a thin layer of darth 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 cooler denser parts sink
convergent boundary
when two plates come together
mountains
uplift of crustal plates that form elevanted landmasses
volcanoes
a vent or fissure in earth surface through which magma and gases are expelled
divergent boundary
when tectonic plates split apart
transform boundary
when tectonic plates slide past each other.
fault
break in the crust . the movement cause seismic wave which produces earthquakes
mid ocean ridge
a long ridge underwater volcanoes between two diverging oceanic plates
subduction zone
a plate where one tectonic plate sink under another and melts also forms a trench