Chapter Seven: Oceans

• 7.1 Introduction to Oceans

• 7.2 Waves

• 7.3 Shallow Marine Environments

• 7.4 The Ocean Floor

7.4 The Ocean Floor• Many of the important features of the oceans are

hidden in deep water.• The continental margin is the region around

continents that includes the:– continental shelf,– continental slope, and– continental rise.

7.4 Features of the ocean floor• Maps can show the

location of the continental shelf (light blue areas).

• The true ocean floor is called the abyssal plain. (dark blue)

• It is flat and smooth because a thick layer of sediment covers its features.

7.4 The deep ocean floor• A barrier island is a

low, sandy island that lies parallel to the shoreline.

• A bank is a low, flat region on the continental shelf.

• A seamount is a steep-sided mountain that rises from the ocean floor.

7.4 The deep ocean floor• A guyot is a seamount

that has eroded so that it has a flat top and is underwater.

• Mid-ocean ridges mark places where two tectonic plates are separating and new ocean crust is being made.

• Deep-ocean trenches are the deepest parts of the ocean.

Water Safety Connection

• Rip currents can cause a swimmer to be pulled out to sea.

• A rip current forms when water piles up near the shore and moves away from the shore all at one time.

Rip Currents

Activity • You will plot a sailboat route for circumnavigating the globe from the coast of Massachusetts to the coast of California.

Circumnavigating the Globe