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