Chapter 14 The Ocean Floor

71% of Earth’s surface is ocean.

Oceanography = the study of the world ocean

World Ocean is divided into…• Pacific• Atlantic• Indian• Arctic (north)

Age of the Ocean Floor

Mapping the Ocean Floor:

Bathymetry = measurement of the ocean depths and charting of the shape or topography of the ocean floor.

Los Angeles, CA

HMS Challenger = 1872-1876 voyage to map ocean floor

Sonar = Sound Navigation And Ranging

Transmits sound waves which bounce off ocean floor.

Time it takes for the waves to return to the ship tells distance (depth) traveled.

Flash: Ocean Floor Sonar

Sonar … Using a back and forth motion across the ocean to map the ocean floor is called “mowing the lawn.”

Satellites and the Ocean Floor

Measuring the ocean floor from space.

Google Earth Oceanhttp://www.pcadvisor.co.uk/tv/index.cfm?&caid=8&vid=110446

Flash: Ocean Floor 1Flash: Ocean Floor 2Flash: Ocean Floor 3

Submersibles = vehicles that are capable of going underwater1st SubmersibleWilliam Beebe in his “bathysphere.”

Piccard’s “Trieste.”

“Alvin” working in the Marianas Trench..”

“Sea Cliff II” working in the Marianas Trench..”AUV (autonomous underwater vehicle)

Chapter 14.2 Ocean Floor Features

Ocean Floor Regions:

1. Continental Margins2. Ocean Basin Floor3. Mid-Ocean Ridge

Pg 401 Figure 6

Continental Shelf = gently sloping submerged surface from the shoreline to the drop off.

Continental Margins

Continental Rise = steeper and wider incline

Continental Margins

Deep Ocean Trenches = long, narrow creases (canyons) in the ocean floor.

Ocean Basin Floor