powerful seismic sea wave that can travel thousands of kilometers in all directions and that begins over an earthquake focus
vibrations caused by breaking rocks along faults
remains or traces of a once living organism reserved by rock
hypothesis proposed by alfred wegener that the states that continents have moved slowly to their current locations on earth
continental drift
single large landmass made up of all the continents connected together that broke apart a long time ago
theory that magma from below earths crust is forced upward toward the suface of the mid-ocean ridge, flows from the cracks as the seafloor spreads apar and becomes solid as it cools, forming new seafloor
seafloor spreading
waves of energy that reach earths surface during an earthquake, travel outward from the epicenter, and move rock particles up andn down, and side to side
surface waves
theory that earths crust and upper mantle are broken into sections that move around on a plastic like layer of the mantle
plate tectonics
cycle of heating , rising , cooling, and sinking that is thought to be the force behind plate tectonics
convection current
the person who created the plate tectonic theory
alfred wegener
scientist who studies earhquakes and seismic waves
device used by seismologist to record primary, secondary surface waves from an earthquake
energy waves that are produced at and travel outward from the earthquakes focus
seismic waves
waves that travel outward from an earthquakes focus and move through earth by causing particles in rocks to vibrate at right angles to the direction of the wave
secondary waves
measure of the energy released by an earthquake
in an earthquake, the point beneath earths surface where energy release occurs
point of earths surface directly above an earthquakes focus
a reegion where the rigid plates are moving apart , typified by the mid ocean ridge
divergent boundary
a body of molten rock found beneath the earths crust
surface alonf where rocks break and move