Chapters 14, 15,

16 Oceanography

Oceanography Essential Questions1 . How does topography of the ocean floor compare with that on land?2. What factors affect the density of ocean water?3. What are the three main zones of the open ocean?4. How do ocean currents affect climate?5. How are density currents formed?

The Topography of the Ocean

Mapping the Ocean Floor

14.2 Ocean Floor Features

The ocean floor regions are the ____________margins, the ocean ________floor, and the mid-ocean _______.

______________Margins

14.2 Ocean Floor Features

In the Atlantic Ocean, thick layers of _________ __________cover the continental margin. This region has very little _________or ______________activity.

A ____________margin is the zone of transition between a ___________and the adjacent ocean ________floor.

Atlantic Continental Margin

Continental Margins In the Pacific Ocean, oceanic crust

________beneath continental crust. This force results in a _________continental margin that experiences both _________activity and _____________.

14.2 Ocean Floor Features

Continental Margins

14.2 Ocean Floor Features

Continental ________• A continental __________is the gently sloping

submerged _________extending from the _____________.

• Continental ___________contain important ___________deposits, large reservoirs of _____and natural _______, and huge _______and ___________deposits.

Continental Margins

14.2 Ocean Floor Features

Continental Slope_______• A continental _________is the steep gradient that

leads to the deep-ocean __________and marks the seaward ________of the continental _______.

• A submarine ___________is the seaward extension of a ___________that was cut on the continental __________during a time when sea level was lower—a ___________carved into the outer continental shelf, slope, and rise by turbidity currents.

• A turbidity _________is the downslope movement of dense, ___________-laden water created when _____and ______on the continental ______and _________are dislodged and thrown into suspension.

Submarine Canyons

Continental Margins

14.2 Ocean Floor Features

Continental _________• A continental ________is the gently sloping

surface at the base of the continental ________.

Ocean ___________Floor

14.2 Ocean Floor Features

The ocean _________floor is the area of the deep-ocean floor between the continental _________and the oceanic ________.

• ____________form at the sites of plate _____________where one moving plate descends beneath another and plunges back into the mantle.

Deep-Ocean _____________

Ocean ___________Floor

14.2 Ocean Floor Features

Abyssal _____________• An abyssal __________is a very level area of

the deep-ocean ___________, usually lying at the foot of the continental ___________.

• The _____________that make up abyssal plains are carried there by turbidity ___________or are deposited as suspended sediment settles out.

___________and ___________• A _______________is an isolated volcanic peak

that rises at least _________meters above the deep-ocean floor, and a _________is an eroded, submerged ____________________.

Abyssal Plain Cross Section

Mid-Ocean ______________

14.2 Ocean Floor Features

A mid-ocean __________is found near the center of most ocean basins. It is an interconnected system of underwater mountains that have developed on newly formed ocean crust.

Seafloor ______________• Seafloor _______________is the process by

which plate tectonics produces new oceanic lithosphere at ocean ridges.

• New ocean floor is formed at mid-ocean ___________as magma rises between the ______________plates and cools.

Mid-Ocean ______________

14.2 Ocean Floor Features

Hydrothermal __________• Hydrothermal ___________form along mid-

ocean ______________. These are zones where mineral-rich water, heated by the hot, newly-formed oceanic crust, escapes through cracks in the oceanic crust into surrounding water.

_______________

15.1 The Composition of Seawater

____________is the total amount of solid material dissolved in water.

Because the proportion of dissolved substances in seawater is such a small number, oceanographers typically express __________in parts per _____________.

Most of the salt in seawater is ________ _____________, common table ________.

___________

15.1 The Composition of Seawater

Sources of Sea __________• _____________weathering of rocks on the

continents is one source of elements found in seawater.

• The second major source of elements found in seawater is from Earth’s _____________.

Salts in Seawater

_______________ Processes Affecting ______________

15.1 The Composition of Seawater

• Processes that decrease _________________:

• Processes that increase ___________________:

- Precipitation

- ________________from land

- Icebergs ________________

- Sea ice ___________

- Evaporation

- __________________of sea ice

Natural Processes Affecting Salinity

Ocean Temperature _______________ The ocean’s surface water temperature

varies with the amount of solar _____________received, which is primarily a function of _______________.

15.1 The Composition of Seawater

• The _____________is the layer of ocean water between about ____meters and ______meters where there is a rapid change of temperature with depth.

Temperature Variation with _____________

• The ______________is a very important structure because it creates a barrier to marine life.

Variations in Ocean Surface Temperature

Variations in Ocean Water Temperature

Ocean ____________Variation __________is defined as ________per unit

__________. It can be thought of as a measure of how heavy something is for its size.

15.1 The Composition of Seawater

• Seawater ____________is influenced by two main factors: __________and ______________.

Factors Affecting Seawater ____________

Ocean _________________Variation ______________Variation with Depth

15.1 The Composition of Seawater

• The ___________is the layer of ocean water between about _____meters and _______meters where there is a rapid change of density with depth.

Variations in Ocean Water Density

Ocean _____________ Oceanographers generally recognize a

three-layered structure in most parts of the open ocean: a shallow _________mixed zone, a ___________zone, and a ________zone.

15.1 The Composition of Seawater

_______________Zone

• _______-warmed zone

• Zone of mixing

• Shallow (300 to 450 meters)

Ocean ___________ ____________Zone

15.1 The Composition of Seawater

___________Zone

• Constant high-density water

• Temperatures are just a __________degrees above freezing.

• ____________never reaches this zone.

• Thermocline and pycnocline

• Between ________layer and ___________zone

Ocean Zones

Classification of Marine __________ Marine _____________can be classified

according to where they live and how they move.

15.2 The Diversity of Ocean Life

______________• __________include all organisms—algae,

animals, and bacteria—that drift with ocean currents.

• _______________are algal plankton, which are the most important community of primary producers in the ocean.

• __________________are animal plankton.

______________

Classification of Marine ___________ __________

15.2 The Diversity of Ocean Life

____________

• ____________include all animals capable of moving ______________of the ocean currents, by swimming or other means of propulsion.

• ___________describes organisms living on or in the ocean _____________.

____________

_____________

Marine Life __________ Three factors are used to divide the ocean

into distinct marine life _______: the availability of ________, the distance from _________, and the water __________.

15.2 The Diversity of Ocean Life

Availability of ___________• The _______________zone is the upper part of

the ocean into which ____________penetrates.

Marine Life _____________ Distance from ___________

15.2 The Diversity of Ocean Life

• The _____________zone is the strip of land where the land and ocean meet and overlap, or the zone between high and low ___________.

• The __________zone is the marine-life zone that extends from the low-_________line out to the shelf _______________.

• The ______________zone is the marine-life zone beyond the continental _____________.

Marine Life Zones

Marine Life Zones Water ____________

15.2 The Diversity of Ocean Life

• The ______________zone is open zone of any depth. Animals in this zone swim or float ______.

• The __________zone is the marine-life zone that includes any sea-__________surface regardless of its distance from _____________.

• The ______________zone is a subdivision of the ___________zone characterized by extremely high pressures, low temperatures, low oxygen, few nutrients, and no sunlight.

Marine Life Zones Hydrothermal ____________

15.2 The Diversity of Ocean Life

• Here seawater seeps into the ocean ___________through ___________in the crust.

• At some _____________, water temperatures of 100oC or higher support communities of organisms found nowhere else in the world.

Hydrothermal Vents

Tube Worms Found Along Hydrothermal Vents

Surface Circulation

16.1 Ocean Circulation

Ocean ________________is the mass of ocean water that flows from one place to another.

Surface _____________• Surface _______________are movements of water that flow

horizontally in the upper part of the ocean’s surface.

• Surface ________________develop from friction between the ocean and the wind that blows across its surface.

Ocean Surface Currents

Surface Circulation ______________

16.1 Ocean Circulation

• __________________are huge circular-moving current systems that dominate the surfaces of the oceans.

• The _________________effect is the deflection of currents away from their original course as a result of Earth’s rotation.

Surface Circulation Ocean _____________and ___________

16.1 Ocean Circulation

• When _______________from low-latitude regions move into higher latitudes, they transfer heat from warmer to cooler areas on Earth.

• As cold water ________________travel toward the equator, they help moderate the warm temperatures of adjacent land areas.

False-Colored Satellite Image of the Gulf Stream

Surface Circulation _________________

16.1 Ocean Circulation

• __________________is the rise of cold water from deeper layers to replace warmer surface water.

• _______________brings greater concentrations of dissolved nutrients, such as nitrates and phosphates, to the ocean surface.

Effects of Upwelling

Deep-Ocean Circulation ________________Currents

16.1 Ocean Circulation

• ________________currents are vertical currents of ocean water that result from density differences among water masses.

• An increase in seawater _______________can be caused by a decrease in temperature or an increase in salinity.

Deep-Ocean Circulation High ______________

16.1 Ocean Circulation

• Most water involved in deep-ocean currents begins in high latitudes at the surface.

_______________• Density currents can also result from increased salinity of ocean

water due to evaporation.

Deep-Ocean Circulation A ________________Belt

16.1 Ocean Circulation

• In a simplified model, ocean circulation is similar to a ___________belt that travels from the Atlantic Ocean, through the Indian and Pacific Oceans, and back again.

Conveyor Belt Model

Cross Section of the Arctic Ocean