| A | B |
|---|
| Continental Margin | region of the sea floor that contains the shelf and slope |
| Continental Shelf | part of the continent that is underwater |
| Ocean basin floor | begins where the slope ends, region made up of mountains, ridges, threnches, valleys, rifts, guyots, abysssal plains, and canyons plateau |
| Abyssal Plain | vast smooth areas on floor |
| Trenches | cracks on the earth's crust, deepest part of the ocean |
| 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 characterized by frequent earthquakes and volcanoes |
| Island | seamount that rises above the surface of the water |
| Continental Slope | Where water deepens abruptly and the edge of the continental land mass drops off |
| Water | 75% of the earth's surface is covered with water |
