Oceonagraphy

4. Zone: The uppermost layer of the ocean, where sunlight penetrates.
6. Aquatic animals that can swim and move independently of water currents.
9. An underwater mountain rising from the ocean floor that does not reach the surface.
10. A layer in a body of water where the temperature changes rapidly with depth.
11. Plain: A flat, almost level area of the deep-ocean basin.
12. Zone: The deepest layer of the ocean, found in ocean trenches.
14. A series of ocean waves with extremely long wavelengths caused by large-scale disturbances.
16. Zone: The layer of the ocean at depths between 4,000 and 6,000 meters.
17. Ridge: An underwater mountain range formed by plate tectonics.
19. The concentration of salts in water.
20. Vent: An opening in the sea floor out of which heated mineral-rich water flows.

1. Slope: The steep slope where the continental shelf drops to the deep ocean floor.
2. The rising of cold, nutrient-rich water from deep in the ocean to the surface.
3. Shelf: The extended perimeter of each continent, which lies submerged under relatively shallow seas.
5. Organisms that live on, in, or near the seabed.
7. Zone: The middle layer of the ocean, receiving very little light.
8. Zone: The deep ocean layer, where no sunlight reaches.
13. Reef: A diverse underwater ecosystem held together by calcium carbonate structures secreted by corals.
15. Small and microscopic organisms drifting or floating in the sea.
18. A deep, narrow depression in the ocean floor, often caused by tectonic activity.