science

2. in an earthquake, the point beneath Earth's surface where energy release occurs
4. current cycle of heating, rising, cooling, and sinking that is thought to be the force behind plate tectioncs
7. rigid, outermost layer of Earth that is about 100km thick, and is composed of the crust and part of the upper mantle
8. waves waves that travel outward from an Earthquake's focus and cause particles in rocks to move back and forth in the same direction the wave is moving
9. point of Earth's surface directely above an earthquake's focus
10. scientist who studiesearthquakes and seismic waves
11. device used by seimologists to record primary, secondary, suface waves from earthquakes
14. fault break in rock due to compression forces, where rocks above the fault surface move upward and over the rocks below the fault surface
15. fault break in rock due to tension forces, where rock above the fault surface moves downward in relation to rock below the fault surface
17. measure of the energy released by an earthquake
18. core liquid core that surrounds Earth's solid inner core, and that is made mostly of iron
19. waves energy waves that are produced at and travel outward from the earthquake's focus
20. single large landmass made up of all the continents connected together that broke apart 200 million years ago

1. drift hypothesis proposed by Alfred Wegener that the states that continents have moved slowly to their current locations on Earth
3. waves waves that travel outward from an earthquke's focus and move through Earth by causing particles in rocks to vibrate at right angles to the direction of the wave
5. core very dense, solid center od the Earth that is made of mostly iron with smaller amounts of oxygen, silicon, sulfur, or nickel
6. plastic-like layer below the lithosphere
11. fault break in rock due to shearing forces, where rocks on either side of the fault suface move past each other with little upward or downward movement
12. Earth's outermost layer, which varies in thickness from about 5km to 60km and is separated from the mantle by the Moho Discontinuity
13. surface along which rocks break and move
16. largest layer inside Earth, lying directly above the outer core and that is made mostly of silicon, oxygen, magnesium, and iron