Exploring the Oceans

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Chapter 13
Exploring the Oceans
Preview
Section 1 Earths Oceans Section 2 The Ocean
Floor Section 3 Life in the Ocean Section 4
Resources from the Ocean Section 5 Ocean
Pollution
Concept Mapping
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Section 1 Earths Oceans
Chapter 13
Bellringer
Look at a photo of Earth taken from space.
Predict the percentage of Earths surface that is
covered by water. Write your prediction in your
science journal.
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Section 1 Earths Oceans
Chapter 13
Objectives

• List the major divisions of the global ocean.
• Describe the history of Earths oceans.
• Identify the properties of ocean water.
• Describe the interactions between the ocean and
  the atmosphere.

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Section 1 Earths Oceans
Chapter 13
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

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Section 1 Earths Oceans
Chapter 13
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Section 1 Earths Oceans
Chapter 13
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.
• The rain filled the deeper levels of Earths
  surface and the first oceans began to form.

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Section 1 Earths Oceans
Chapter 13
How Did the Oceans Form?, continued

• The shape of the oceans has changed over time.

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Section 1 Earths Oceans
Chapter 13
Characteristics of Ocean Water

• Dissolved Gases Nitrogen, oxygen, and carbon
  dioxide are the main gases dissolved in ocean
  water.

• Solids Sodium chloride, or table salt, is the
  most abundant dissolved solid in the ocean. Other
  solids are also found in ocean water.

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Section 1 Earths Oceans
Chapter 13
Characteristics of Ocean Water, continued

• Salinity is a measure of the amount of dissolved
  solids in a given amount of liquid.
• Changes in Salinity Climate and water movement
  affect salinity. Costal water in cool, humid
  places has a low salinity. Slow-moving bodies of
  water have higher salinity than other parts of
  the ocean do.

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Section 1 Earths Oceans
Chapter 13
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Section 1 Earths Oceans
Chapter 13
Characteristics of Ocean Water, continued

• Temperature Zones The temperature of ocean
  water decreases as depth increases.

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Section 1 Earths Oceans
Chapter 13
Characteristics of Ocean Water, continued

• Surface Temperature Changes 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.

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Section 1 Earths Oceans
Chapter 13
The Ocean and 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 Earths water is in
  the ocean.

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Section 1 Earths Oceans
Chapter 13
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Section 1 Earths Oceans
Chapter 13
A Global Thermostat

• The ocean regulates atmospheric temperatures.
• A Thermal Exchange 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 with the currents.

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Section 2 The Ocean Floor
Chapter 13
Bellringer
Pretend you have walked off the edge of North
America and into the depths of the Atlantic
Ocean. As you walk along the ocean floor toward
Europe, what do you see? Draw the ocean floor as
you imagined it.   Illustrate your answer in your
science journal.
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Section 2 The Ocean Floor
Chapter 13
Objectives

• 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.

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Section 2 The Ocean Floor
Chapter 13
Studying the Ocean Floor

• Seeing by Sonar Scientists use sonar to
  determine the oceans depth.
• Oceanography via Satellite Scientists use
  images from the satellite Seasat to study ocean
  currents.
• Studying the Ocean with Geosat Scientists use
  the Geosat satellite to measure slight changes in
  the height of the oceans surface.

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Section 2 The Ocean Floor
Chapter 13
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Section 2 The Ocean Floor
Chapter 13
Revealing the Ocean Floor

• Regions of the Ocean Floor The two regions of
  the ocean floor are the continental margin and
  the deep-ocean basin.
• Underwater Real Estate The continental margin
  and the deep-ocean basin are subdivided into
  different areas and have different features, as
  shown on the next two slides.

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Section 2 The Ocean Floor
Chapter 13
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Section 2 The Ocean Floor
Chapter 13
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Section 2 The Ocean Floor
Chapter 13
Exploring the Ocean with Underwater Vessels

• Piloted Vessels Alvin and Deep Flight Alvin
  and Deep Flight are two research vessels that can
  reach some of the deepest parts of the ocean.
• Robotic Vessels JASON II and Medea 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 the sea
  floor.

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Section 3 Life in the Ocean
Chapter 13
Bellringer
Imagine you are a marine biologist who must
classify marine life into three groups. What
criteria would you use in your classification
system?   Record your response in your science
journal.
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Section 3 Life in the Ocean
Chapter 13
Objectives

• Identify the three groups of marine life.
• Describe the two main ocean environments.
• Identify the ecological zones of the benthic and
  pelagic environments.

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Section 3 Life in the Ocean
Chapter 13
Three Groups of Marine Life

• Organisms that float or drift freely near the
  oceans 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.

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Chapter 13
Section 3 Life in the Ocean
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Section 3 Life in the Ocean
Chapter 13
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.

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Section 3 Life in the Ocean
Chapter 13
The Benthic Environment, continued

• 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.

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Section 3 Life in the Ocean
Chapter 13
The Benthic Environment, continued

• The Sublittoral Zone 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.

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Section 3 Life in the Ocean
Chapter 13
The Benthic Environment, continued

• The Bathyal Zone 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.

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Section 3 Life in the Ocean
Chapter 13
The Benthic Environment, continued

• The Abyssal Zone 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.

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Section 3 Life in the Ocean
Chapter 13
The Benthic Environment, continued

• The Hadal Zone 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.

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Section 3 Life in the Ocean
Chapter 13
The Pelagic Environment

• The zone near the oceans surface and at the
  middle depths is called the pelagic environment.
• 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.

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Section 3 Life in the Ocean
Chapter 13
The Pelagic Environment, continued

• The Neritic Zone The neritic zone is a warm,
  shallow zone that covers the continental shelf.
• The neritic zone contains the largest
  concentration of marine life.
• The neritic zone receives more sunlight than
  other ocean zones, allowing plankton to grow and
  serve as a food supply.

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Section 3 Life in the Ocean
Chapter 13
The Pelagic Environment, continued

• The Oceanic Zone 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.
• Organisms are more spread out in the oceanic
  zone.

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Section 4 Resources from the Ocean
Chapter 13
Bellringer
Tabitha drove her car to the market to buy a tuna
steak for dinner. When she got home, she poured
herself a glass of water, fired up her gas grill,
and cooked the tuna. Identify four of Tabithas
items or activities that involve resources
obtained from the sea.   Record your response in
your science journal.
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Section 4 Resources from the Ocean
Chapter 13
Objectives

• List two ways of harvesting the oceans living
  resources.
• Identify three nonliving resources in the ocean.
• Describe the oceans energy resources.

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Section 4 Resources from the Ocean
Chapter 13
Living Resources

• Fishing the Ocean Fish are the larges group of
  organisms take from the ocean.
• Farming the Ocean People have begun to raise
  ocean fish and other organisms in fish farms to
  help meet the demand for seafood.
• Savory Seaweed Many types of seaweed are
  harvested from the ocean for use as food.

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Section 4 Resources from the Ocean
Chapter 13
Nonliving Resources

• Oil and Natural Gas Oil and natural gas are
  used for energy and are found under layers of
  impermeable rock.
• Searching for Oil Scientists use seismic
  equipment to find oil and natural gas under the
  ocean floor.

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Section 4 Resources from the Ocean
Chapter 13
Nonliving Resources, continued

• Fresh Water and Desalination Fresh water can be
  collected for human use by removing the salt from
  ocean water.
• Sea-Floor Minerals Scientists estimate that 15
  of the ocean floor is covered with mineral-rich
  nodules. However, mining them is costly and
  difficult.
• Tidal Energy is energy generated from the
  movement of the tides.

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Section 4 Resources from the Ocean
Chapter 13
Tidal Energy
Click below to watch the Visual Concept.
Visual Concept
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Section 4 Resources from the Ocean
Chapter 13
Nonliving Resources, continued

• Wave Energy 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.

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Section 5 Ocean Pollution
Chapter 13
Bellringer
How does ocean pollution affect your life? What
are possible ways you contribute to
ocean pollution in your daily life?   Write your
answers in your science journal.
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Section 5 Ocean Pollution
Chapter 13
Objectives

• 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.

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Section 5 Ocean Pollution
Chapter 13
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.

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Section 5 Ocean Pollution
Chapter 13
Point-Source Pollution

• Trash Dumping Dumping trash in the deeper parts
  of the ocean is a common practice in many
  countries.
• Effects of Trash Dumping Trash thrown in the
  ocean can be harmful to ocean organisms.
• Sludge Dumping Sludge is the solid waste
  removed from raw sewage. Sludge can pollute
  beaches and kill marine life.

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Section 5 Ocean Pollution
Chapter 13
Point-Source Pollution, continued

• Oil Spills If not handled properly, oil
  transports can cause oil spills.

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Section 5 Ocean Pollution
Chapter 13
Point-Source Pollution, continued

• Effects of Oil Spills Oil spills can harm or
  kill many plants and animals.
• Preventing Oil Spills New technology is being
  used to safeguard against oil spills. Oil tankers
  are now being built with two hulls instead of one.

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Section 5 Ocean Pollution
Chapter 13
Saving Our Ocean Resources

• Nations Take Notice Many international
  agreements and laws restrict ocean pollution.
• Citizens Taking Charge People have demanded
  that their governments work to solve ocean
  pollution and have begun organizing beach
  cleanups.
• Action in the United States The U.S. has passed
  laws to control local pollution.

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Exploring the Oceans
Chapter 13
Concept Mapping
Use the terms below to complete the concept map
on the next slide.
ecological zones benthos intertidal zone benthic zone nentic zone marine life oceans plankton oceanic zone

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Exploring the Oceans
Chapter 13
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Exploring the Oceans
Chapter 13