Wegener's hypothesis that Earth continents were joined as a single landmass, "pangea" that broke apart 200 mya and slowly moved to their present positions.
Ancient land mass made up of all the continents that began to break apart about 200 mya.
device used to map the ocean floor that detects small changes in the magnetic fields
When earth's magnetic field changes polarity between normal and reverse
study of earth's magnetic record using data gathered from iron bearing minerals in rocks that have recorded the orientation of earth's magnetic field at the time of their formation
The measuring line on a map that shows points of the same age; formed at the same time
The hypothesis that new crust is formed at midocean ridges and destroyed at deep sea trenches; occurs in a continuous cycle of magma intrusion and spreading
Huge pieces of earth's crust that cover its surface and fit together at their edges
Place where two of earth's tectonic plates are moving apart; associated with volcanism, earthquakes, and high heat flow, and is found primarily on the sea floor
Long, narrow depression that forms when continental crust begins to separate at a divergent boundary
Place where two tectonic plates are moving toward each other; is associated with trenches, islands arcs, and folded mountains
Process by which one tectonic plate slips beneath another tectonic plate
Place where two tectonic plates slide horizontally past each other; is characterized by long faults and shallow earthquakes
Tectonic process associated with convection currents in earth's mantle that occurs when the weight of an elevated ridge pushes an oceanic plate toward a subduction zone
Tectonic process associated with convection currents in Earth's mantle that occurs as the weight of the subducting plate that pulls the trailing lithosphere into a subduction zone