Oceanography Test Review

1. Oceanography Test Review 11/19/2010

2. Oceanography • 1. 70 percent of the earth’s surface is covered by water. • 2. The four major oceans are: Pacific, Atlantic, Indian, and Arctic • 3. The ocean that has the greatest average depth is Pacific • 4. The largest of Earth’s oceans is Pacific • 5. Thesouthern hemisphere is covered by much more water than the northernhemisphere.

3. Oceanography cont. • 6. The steep continental slope merges into a more gradual incline known as the continental rise , where trenches do not exist. • 7. Deep, steep sided valleys that originate on the continental slope and may extend to the ocean basin floor are called submarine canyons. • 8. The volcanic peaks on the ocean floor are calledseamonts.

4. Oceanography cont. • 9. Describe deep ocean trenches. They are long narrow depressions where the plate plunges back into the mantle and form the deepest part of the ocean. • 10. The scientists use sonar to measure ocean depth. • 11. The speed of sound in water is 1500 meters per second. • 12. Difference in ocean-surface height can be measured by satellites. • 13. The three major regions of the ocean floor are: continental margins, ocean basin floor, and Mid-Ocean ridge

5. Oceanography cont. • 14. Turbidity currents are associated with the downslope movements of sediment rich water. • 15. Seamounts are volcanoes that form on the ocean floor. • 16. Mid-ocean ridges are associated with mountainous topography. • 17. The gently sloping submerges surface extending from the shoreline toward the deep ocean is called continental shelf.

6. Oceanography cont. • 18. Important mineral deposits (including large reservoirs of oil and natural gas) are associated with continental shelves. • 19. Volcanic activity, earthquakes, and plate interactions occur at continental margin in the Pacific Ocean. • 20. The most level places on Earth are parts of the ocean abyssal plain. • 21. Trenches are the most deep parts of the ocean.

7. Oceanography cont. • 22. Hydrothermal vents are mineral rich water, heated by newly formed oceanic crust, and escapes through cracks in the ocean floor. • 23. The seafloor spreading occurs at divergent plates. • 24. Calcareous ooze is an example of biogenoussediments. • 25. Heat from the Earth’s interior and pressure from overlying rock transform the remains of marine sediments into oil and natural gas • 26. Oil (as an ocean resources )can be found in Persian Gulf, Gulf of Mexico, and North Sea

8. Oceanography cont. • 27. Sand and gravel are second in economic value to oil. • 28. When seawater evaporates, the concentration of salts increases until the salts precipitate out of the solution. • 29. The salinity of seawater is 3.5 percent • 30. The most abundant salt in the sea is sodium chloride • 31. One thousand grams of seawater consists of 35 grams of dissolved substances.

9. Oceanography cont. • 32. The highest salinity is found in an area with a high rate of evaporation. • 33. The ocean layer of rapid temperature change with depth is thermocline. • 34. Density is mass divided by volume. • 35. The factors affecting the density of seawater are: temperature and salinity • 36. The water’s vertical position in the ocean is determined by density.

10. Oceanography cont. • 37. Plankton is all organisms that drift with the currents. • 38. The organisms that live on or in the ocean floor are calledbenthos. • 39. The ocean bottom is cold, dark, and quiet • 40. The ocean zone characterized by high water pressure, low temperature, and no sunlight is abyssal zone.

11. Oceanography cont. • 42. The open ocean at any depth is called pelagic zone. • 43. The chemical energy that is transferred from algae to marine animals by chemosynthesis. • 44. The energy that drives surface ocean currents comes from wind. • 45. Define Coriolis effect. the deflection of currents away from their original course as a result of Earth’s rotation.

12. Oceanography cont. • 46. Because of the Earth’s rotation, currents are deflected to the right in the northern hemisphere and to the left in the southern hemisphere. • 47. Ocean currents that move towards the poles are warm. • 48. The Gulf stream affects the climate of Great Britian.

13. Oceanography cont. • 49. The rising of cold mineral rich water from the deeper layers to replace warmer surface water is called upwelling. • 50. A fetch is the distance wind moves across open water. • 51. Waves begin to “feel bottom” when the water depth is equal to half the wavelength.

14. Oceanography cont. • 52. The tidal pattern that has two high tides and two low tides each day is called semidiurnal. • 53. A sandbar the completely crosses a bay, closing it off from the deep ocean, is calledbaymouth bar • 54. A ridge of sand projecting into a bay and often having a hooked end is a spit.