Chapter 14

Oceanography Science that draws on the methods and

knowledge of geology, chemistry, physics, and biology to study all aspects of the ocean.

The Blue Planet Nearly 71 percent of Earth’s surface

is covered by the global ocean

Earths Oceans The world ocean can be divided into four main ocean

basins—the Pacific Oceanthe Atlantic Oceanthe Indian Oceanthe Arctic Ocean

Ocean FactsThe Pacific Ocean is the largest and has the

greatest depthThe Atlantic Ocean is about half the size of the

Pacific and not quite as deepThe Indian Ocean, largely a southern

hemisphere body, is slightly smaller than the Atlantic

The Arctic Ocean is about 7 percent of the size of the Pacific

Ocean FactsAverage ocean depth is 3800 m

compared with average continental elevation of 840 m above sea level

Mapping the Ocean FloorThe topography of the ocean floor is as

diverse as that of the continentsBathymetry is the measurement of ocean

depths and the charting of the shape or topography of the ocean floor.

Mapping the Ocean FloorSonar is an acronym for sound

navigation and ranging. It works by transmitting sound waves toward the ocean bottom.

Simple sonar-obtains depth of a particular areaMultibeam sonar-obtains a profile of a narrow strip of

the seafloor every few seconds (“Moving the lawn”)

SatellitesSatellites are able to measure small

differences by bouncing microwaves off the ocean surface.

Scientists have discovered that the ocean surface is not perfectly flat.

Gravitational pull of undersea mountains elevate the surface, trenches cause slight depressions

Submersibles are small underwater crafts used for deep-sea research.Some are mannedOthers are remote controlled

Remember the ocean floor is VERY diverse.

The Ocean Floor The ocean floor regions are the:

continental marginsthe ocean basin floorthe mid-ocean ridge

Continental marginsIs the zone of transition between a continent and

the adjacent ocean basin floor.Two main types

Active- volcanic activity and earthquakes.Passive- very little volcanic or earthquake

activity

A continental slope is the steep gradient that leads to the deep-ocean floor and marks the seaward edge of the continental shelf.

Draw the next slide in your notes Pg 402

DRAW AND LABEL

Ocean Basin FloorThe ocean basin floor is the area of the deep-

ocean floor between the continental margin and the oceanic ridge.

Features of the Ocean Floor Deep-Ocean TrenchesAbyssal plainSeamounts

Mid- Oceanic Ridge It is an interconnected system of

underwater mountains that have developed on newly formed ocean crust.

A spreading center

HomeworkRead Chapter 14.2 and answer questions 1-

6 on page

405

Read Chapter 14.3 and answer Questions 1-4 on page 409