Ocean Topography Chapter 13

What problems must we overcome to study the ocean floor?

Sunlight doesn’t penetrate far below the surface. 1. Darkness Sunlight doesn’t penetrate far below the surface.

The water is only a few degrees above freezing 2. Temperature The water is only a few degrees above freezing

3. Pressure The mass of the water pushing down from above creates tremendous pressure

What are the solutions to problems in studying the ocean floor?

Sonar SOund NAvigation and Ranging Measures how quickly the sounds return to the ship Calculates the distance to an object

Other Solutions Scuba Submersibles Satellites Remote Underwater Manipulator Gravity Mapping Weight attached to a string

What have we discovered on the ocean floor?

Continental Shelf Gently sloping, shallow area of the ocean floor that extends outward 3 – 1,300 km from the edge of a continent.

Continental Slope An incline leading down from edge of continental shelf, at a depth of about 130 meters.

Volcanic Islands When volcanoes on the ocean floor erupt, they can create mountains so high that their peaks break the surface of the ocean.

Seamounts Mountains entirely underwater. Some have flat tops because their peaks have eroded away

Abyssal Plain A broad area covered with thick layers of mud (sediment formed by the sunken remains of dead organisms from the surface)

Mid-Ocean Ridge An 80,000 km long range of mountains that winds around Earth; has many peaks along both sides of a central valley

Trench A steep-sided canyon in the ocean floor so deep that you can’t see the bottom