| A | B |
|---|
| ocean | large bodies of salt water which contain most of the Earth's water. They are the Atlantic, Pacific, Indian, Arctic, and Southern. |
| sea | a large body of water which is much smaller than an ocean. Some seas are a part of an ocean. Example: The North Sea is connected to both the Atlantic and the Arctic oceans. |
| basin | the ocean floor |
| current | a stream of water that flows through the ocean like a river |
| continental shelf | the underwater edge of a continent |
| continental slope | the steep slope leading from the continental shelf to the ocean floor |
| continental rise | a buildup of sediment on the ocean floor at the bottom of the continental slope. It is a zone of sand and mud stretching from the slope down to the deep ocean floor |
| abyssal plain | the vast flat lands beyond the continental shelf that covers almost half of the deep ocean floor |
| seamount | a huge underwater volcanic mountain that may emerge from the ocean surface as an island |
| trench | a deep valley in the ocean floor |
| mid-ocean ridge | a chain of mountains that wind along all the world's major oceans |
