Oceanography Test Review 11/19/2010

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. The southern hemisphere is covered by much more water than the northern hemisphere.

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 called seamonts.

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

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.

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.

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 biogenous sediments. 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

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.

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.

Oceanography cont. 37. Plankton is all organisms that drift with the currents. 38. The organisms that live on or in the ocean floor are called benthos. 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.

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.

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.

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.

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 called baymouth bar 54. A ridge of sand projecting into a bay and often having a hooked end is a spit.