| A | B |
|---|
| cinder cone | A volcano with very steep sides that erupts with explosive force |
| composite cone | volcano with alternating layers of rock, lava and ash |
| continental drift | theory that the earth's plates move |
| convergent boundary | earth's plates come together |
| core | innermost layer of the earth; iron and nickel |
| crust | the outermost, thinnest, and most solid layer of the earth |
| divergent boundary | places separate or pull apart |
| epicenter | point on the earth's surface directly above an earthquake |
| mantle | middle layer of the earth, sometimes brittle, sometimes like putty |
| continental rock | granite |
| oceanic crust | basalt |
| sea floor spreading | new sea floor is made as the plates move away from each other |
| magma | molten lava |
| shield volcano | gently sloped mountain that erupts without much force |
| transform fault boundary | plates move horizontally past each other |
| San Andreas Fault | large fault line in California |
| Alfred Wegener | developed the theory of plate tectonics |
| Mid Atlantic Ridge | large crack in the Atlantic Sea floor, new ocean floor is forming |
| seismic waves | p waves, s waves and surface waves that occur during an earthquake |
| seismograph | measures the intensity of earthquake waves |
