Exploring the Oceans


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Exploring the Oceans

  1. 1. WARMUP *Have your Vocab Sheets laying out so I can check them* What percentage of earth do you think is covered by water?
  2. 2. EXPLORING THE OCEANS Earth Science: Book H, Chapter 2
  3. 3. SECTION 1: EARTH’S OCEANS By the end of this section, you should be able to:  List the major divisions of the global ocean.  Describe the history of Earth’s oceans.  Identify the properties of ocean water.  Describe the interactions between the ocean and the atmosphere.
  4. 4. DIVISIONS OF THE GLOBAL OCEAN  The largest ocean is the Pacific Ocean.  The other oceans, listed from largest to smallest, are:     the Atlantic Ocean the Indian Ocean the Arctic Ocean the Southern Ocean
  5. 5. HOW DID THE OCEANS FORM?  About 4.5 billion years ago, there were no oceans.  Sometime before 4 billion years ago, water vapor in the atmosphere condensed and fell as rain. rain filled the deeper levels of Earth’s surface and the first oceans began to form.  The  The shape of the oceans has changed over time.
  6. 6.  Need Pangaea image here
  7. 7. CHARACTERISTICS OF OCEAN WATER  Nitrogen, oxygen, and carbon dioxide are the main gases dissolved in ocean water.  Sodium chloride, or table salt, is the most abundant dissolved solid in the ocean. Other solids are also found in ocean water.
  8. 8. CHARACTERISTICS OF OCEAN WATER  Salinity is a measure of the amount of dissolved salts in a given amount of liquid.  If you evaporated 1 kg of ocean water, 965 g of fresh water would be removed and 35 g of salts would remain.
  9. 9. CHARACTERISTICS OF OCEAN WATER  Climate and water movement affect salinity.  Coastal water in cool, humid places has a low salinity.  Slow-moving bodies of water, such as bays, gulfs, and seas, have higher salinity than other parts of the ocean do.
  10. 10. CHARACTERISTICS OF OCEAN WATER  The temperature of ocean water decreases as depth increases.
  11. 11. CHARACTERISTICS OF OCEAN WATER  Surface-zone temperatures vary with latitude and the time of year.  Surface temperatures range from 1ºC near the poles to about 24 ºC near the equator.  The surface zone is heated more in the summer.
  12. 12. THE OCEAN & THE WATER CYCLE  The water cycle is the continuous movement of water from the ocean to the atmosphere to the land and back to the ocean.  The ocean is an important part of the water cycle because nearly all of Earth’s water is in the ocean.
  13. 13. A GLOBAL THERMOSTAT  The ocean regulates atmospheric temperatures.  The ocean absorbs and releases thermal energy much more slowly than dry land does.  The circulation of warm water causes some coastal lands to have warmer climates than they would have without the currents.
  14. 14. SECTION REVIEW p.45 #2-6, 8
  15. 15. WARMUP If you walked off the edge of North America into the depths of the Atlantic Ocean what would you see?
  16. 16. SECTION 2: THE OCEAN FLOOR By the end of this section, you should be able to:  Describe technologies for studying the ocean floor.  Identify the two major regions of the ocean floor.  Classify subdivisions and features of the two major regions of the ocean floor.
  17. 17. STUDYING THE OCEAN FLOOR  Scientists depth. use sonar to determine the ocean’s
  18. 18. STUDYING THE OCEAN FLOOR  Scientists use images from the satellite Seasat to study ocean currents.  Scientists use the Geosat satellite to measure slight changes in the height of the ocean’s surface.
  19. 19. REVEALING THE OCEAN FLOOR  The two regions of the ocean floor are the continental margin and the deep-ocean basin.  The continental margin is made of continental crust and the deep-ocean basin is made of oceanic crust.
  20. 20. REGIONS OF THE OCEAN FLOOR  Continental margin is subdivided into the continental shelf, continental slope, and continental rise.  These divisions are based on depth and changes in slope.
  21. 21. REGIONS OF THE OCEAN FLOOR  The deep-ocean basin consists of the abyssal plain, mid-ocean ridges, rift valleys, and ocean trenches. of these form near the boundaries of Earth’s tectonic plates.  All
  22. 22. REGIONS OF THE OCEAN FLOOR  On parts of the deep-ocean basin not near plate boundaries, there are thousands of seamounts.  Seamounts are submerged volcanic mountains on the ocean floor.
  23. 23. EXPLORING THE OCEAN  Alvin and Deep Flight are two research vessels that can reach some of the deepest parts of the ocean.  JASON II and Medea are a robotic team. JASON II explores the ocean floor. Medea is attached to JASON II with a tether and explores above the sea floor.
  24. 24. SECTION REVIEW p.51 #2-7, 11
  25. 25. WARMUP Imagine you are a marine biologist who must classify marine life into 3 groups. What criteria would you use for your classification system?
  26. 26. SECTION 3: LIFE IN THE OCEAN By the end of this section, you should be able to:  Identify the three groups of marine life.  Describe the two main ocean environments.  Identify the ecological zones of the benthic and pelagic environments.
  27. 27. THREE GROUPS OF MARINE LIFE  Organisms that float or drift freely near the ocean’s surface are called plankton.  Organisms that swim actively in the open ocean are called nekton.  Organisms that live on or in the ocean floor are called benthos.
  28. 28. THE BENTHIC ENVIRONMENT  The benthic environment is the region near the bottom of a pond, lake, or ocean.  The benthic environment is divided into ecological zones based on where different types of benthos live.
  29. 29. THE BENTHIC ENVIRONMENT  The intertidal zone is where the ocean meets the land.  The intertidal zone is exposed to air for part of the day. Organisms found in this zone include starfish, sea anemones, barnacles, crabs, and seaweed.
  30. 30. THE BENTHIC ENVIRONMENT  The sublittoral zone begins at the low-tide limit and extends to the continental shelf, which is about 200 m below sea level.  The temperature, water pressure, and amount of sunlight remain fairly constant in this zone. Coral is found in this zone.
  31. 31. THE BENTHIC ENVIRONMENT  The bathyal zone extends from the continental shelf to the abyssal zone. The depth of this zone ranges from 200 m to 4,000 m below sea level.  Because of the lack of sunlight, few plants are found in this zone. Animals such as sea stars, sponges, and octopuses are found here.
  32. 32. THE BENTHIC ENVIRONMENT  The abyssal zone is the largest ecological zone of the ocean and can reach 4,000 m in depth.  No plants live in this zone. The few animals that can be found include crabs, sponges, sea cucumbers, and worms.
  33. 33. THE BENTHIC ENVIRONMENT  The hadal zone consists of the floor of the ocean trenches and any organisms found there. The depth can reach from 6,000 m to 7,000 m below sea level.  The only organisms that have been found in this zone include a type of sponge, a few species of worms, and a type of clam.
  34. 34. THE PELAGIC ENVIRONMENT zone near the ocean’s surface and at the middle depths is called the pelagic environment.  The  The pelagic environment is above the abyssal zone and beyond the littoral zone.  The two major zones of the pelagic environment are the neritic zone and the oceanic zone.
  35. 35. THE PELAGIC ENVIRONMENT  The neritic zone is a warm, shallow zone that covers the continental shelf.  The neritic zone contains the largest concentration of marine life.
  36. 36. THE PELAGIC ENVIRONMENT  The neritic zone receives more sunlight than other ocean zones, allowing plankton to grow and serve as a food supply.
  37. 37. THE PELAGIC ENVIRONMENT  The oceanic zone includes the volume of water that covers the entire sea floor except for the continental shelf.  The deeper parts of the oceanic zone have colder water temperatures and much greater pressure than the neritic zone.
  38. 38. THE PELAGIC ENVIRONMENT  Organisms zone. are more spread out in the oceanic
  39. 39. SECTION REVIEW p.57 #1-5,7,9
  40. 40. WARMUP Samantha drove her car to the market to buy a tuna steak for dinner. When she got home she poured herself a glass of water, and then fired up her gas grill to cook the tuna. What are 3 items or activities mentioned above that involve ocean resources?
  41. 41. SECTION 4: RESOURCES FROM THE OCEAN By the end of this section, you should be able to: two ways of harvesting the ocean’s living resources.  Identify three nonliving resources in the ocean.  Describe the ocean’s energy resources.  List
  42. 42. LIVING RESOURCES  Fish are the largest group of organisms taken from the ocean.  People have begun to raise ocean fish and other organisms in fish farms to help meet the demand for seafood.
  43. 43. LIVING RESOURCES  Many types of seaweed are harvested from the ocean for use as food.
  44. 44. NONLIVING RESOURCES  Oil and natural gas are used for energy and are found under layers of impermeable rock.  Scientists use seismic equipment to find oil and natural gas under the ocean floor.
  45. 45. NONLIVING RESOURCES  Fresh water can be collected for human use by desalination, the process of removing the salt from ocean water.
  46. 46. NONLIVING RESOURCES  Scientists estimate that 15% of the ocean floor is covered with mineral-rich nodules. However, mining them is costly and difficult.  Nodules form from dissolved substances in sea water that stick to solid objects, such as pebbles.
  47. 47. NONLIVING RESOURCES  The constant motion of waves is a clean, renewable energy resource.  Researchers have found certain areas of the world where wave energy can generate enough electrical energy to make building power plants worthwhile.
  48. 48. SECTION REVIEW p.63 #2-7
  49. 49. WARMUP How do you contribute to ocean pollution in your daily lives?
  50. 50. SECTION 5: OCEAN POLLUTION By the end of this section, you should be able to:  Explain the difference between point-source and nonpoint-source pollution  Identify three different types of point-source pollution.  Describe what is being done to control ocean pollution.
  51. 51. NONPOINT-SOURCE POLLUTION  Pollution that comes from many sources rather than from a single site is called nonpoint-source pollution.  Most ocean pollution is nonpoint-source pollution and can be difficult to regulate and control.
  52. 52. POINT-SOURCE POLLUTION  Dumping trash in the deeper parts of the ocean is a common practice in many countries.  Trash thrown in the ocean can be harmful to ocean organisms.
  53. 53. POINT-SOURCE POLLUTION  Sludge is the solid waste removed from raw sewage. Sludge can pollute beaches and kill marine life.
  54. 54. POINT-SOURCE POLLUTION  If not handled properly, oil transports can cause oil spills.
  55. 55. POINT-SOURCE POLLUTION  Oil spills can harm or kill many plants and animals.
  56. 56. POINT-SOURCE POLLUTION  New technology is being used to safeguard against oil spills. Oil tankers are now being built with two hulls instead of one.
  57. 57. SAVING OUR OCEAN RESOURCES  Many international agreements and laws restrict ocean pollution.  People have demanded that their governments work to solve ocean pollution and have begun organizing beach cleanups.
  58. 58. SAVING OUR OCEAN RESOURCES  The U.S. has passed laws to control local pollution.  Some of these laws include the Clean Water Act and the U.S. Marine Protection, Research, and Sanctuaries Act.
  59. 59. SECTION REVIEW p.69 #2-6