Theory of Plate Tectonics
the theory that the Earth's lithosphere is divided into tectonic plates that move around on top of the asthenosphere because of convection currents
Theory of Continental Drift
proposed by Alfred Wegner, that the continents were once joined together in a continent called Pangea and have since drifted apart; evidence from land features, fossils, and climates
current in Earth's mantle that transfers heat in Earth's interior and is the driving force for plate tectonics
boundary between tectonic plates in which the two plates move away from each other, and new crust is created between them
boundary between two colliding plates, often associated with mountain building ocean trenches and volcanic islands
A boundary where two plates rub together vertically or horizontally in opposite directions forming a fault. Earthquakes occur here.
molten rock beneath the earth's surface
magma that reaches Earth's surface
A mudflow composed of water and volcanic ash. Lahars can be triggered by the flash melting of the snow cap of a volcanic mountain or from heavy rain. Lahars are very dangerous because they can occur suddenly and travel at great speeds.
The point on Earth's surface directly above an earthquake's focus.
The point inside Earth where an earthquake begins
the branch of geology that studies earthquakes
Primary mountain range in the eastern US, rise above the Piedmont - some of the oldest mountains in the world created by convergent boundary upwarping.