| A | B |
|---|
| continental margin | region of sea floor that contains the shelf and slope |
| continental shelf | part of the continent that is under water |
| continental slope | where the edge of the continental land mass drops off |
| continental rise | bottom of continental slope and edge of continental margin, usually characterized by pile of debris |
| ocean basin floor | region that begins where slope ends, made up of mts., ridges, trenches, guyots, etc |
| abyssal plain | vast, smooth areas on floor |
| trenches | cracks in earth's crust, the deepest part of ocean floor |
| guyots | flat-topped underwater volcanic mts. |
| rift | valley that runs along the center of a ridge |
| seamount | isolated mt. rising more than 3000 ft. above ocean floor |
| mid-ocean ridge | undersea mt. ranges characterized by earthquakes and volcanoes |
| volcanic island | volcanic seamount that rises above surface of water |
| 75% | amount of the earth's surface that is covered by water |
