| A | B |
|---|
| contin margin | region of the sea floor that contans the shelf and slope |
| conteinental shelf | part of the continent thet is underwater |
| continental slope | where water deepens abruptly and the edge of the continental land mass drops off |
| ocean basin floor | begins where the slop ends, region made up of mountains, ridges, trenches, valleys, rifts, guyots, abyssal plains, and canyons plateau |
| abyssal plain | vast smoth areas on floor |
| trenches | cracks on the earth's crust, deepest part of the oceans |
| guyots | flat topped volcanic mountains |
| rift | a valley that runs along the center of a ridge |
| seamount | isolated mountain that rises more than 3000 ft. above the sea floor |
| mid-ocean ridge | great undersea mountain ranges chatacterized by frequent earthquakes and volcanoes |
| island | seamount that rises above the surface of the water |
| surface coverage | 75% of the earths surface with water |
