Marine Science Lesson 6

Bathymetry

The study of the seafloor and the features found underwater.

Continental Shelf

A gently sloping area along the edges of continents.

Mid-ocean Ridge

Underwater mountain range.

Abyssal Plain

Flat, featureless plain making up a large part of the seafloor.

Trench

Deepest feature of the ocean, plunging deep below the seafloor.

Continental Slope

A steep slope leading from the edge of a continent down to the sea floor.

Seamount

An underwater mountain with a peak or flat top.

Continental Rise

A hill of sediment at the bottom of the steep slope near the edges of continents.

Submarine Canyon

Steep-sided underwater valley near the edge of a continent.

Plumb Lines

Cable or line with evenly spaced knots used to measure the ocean's depth and map the floor.

Sonar

A technique using echoes to learn about the surrounding environment.

Echolocation

Sound to determine the distance and direction of objects around them.

Melon

Fatty organ in front of the toothed whale's skull.

Terrigenous

Comes from land; example rocks and soil.

Biogenous

Comes from living things; example shells.

Hydrogenous

Formed when they precipitate out of the seawater itself; example: salt.

Foraging

Searching for food.

Ring of Fire

A horseshoe-shaped region around the Pacific Ocean with intense volcanic and earthquake activity.

Mariana Trench

The deepest part of the ocean.

Mauna Kea

Earth's tallest mountain located in Hawaii.

Depth Representation in Seafloor Images

Reds, oranges, and yellows represent shallower areas; blues and purples represent deeper areas.

Side Scan Sonar

Uses gray images to give an image of the sea floor, but not depth info.

Multibeam Sonar

Captures colorful images with depth information.