The Ocean Floor

Revealing the Ocean Floor

The ocean floor has many features, including:  continental shelves – slopes gently down from the edge of the continent  submarine canyons – steep V-shape that cuts through the continental shelf and slope  continental slopes – slopes steeply from the continental shelf  continental rise – sediments pile up at the bottom of the continental slope Continental Margin

 abyssal plains – flat ocean bottom  ocean trenches – very steep-sided narrow cut in the seafloor  mid-ocean ridges – underwater sea mountain range  seamounts – steep-walled, pointed, extinct volcano  volcanoes – underwater volcanoes tall enough to reach above the surface Ocean Basin

Many ocean features have been discovered due to technology. Oceanographers use echo sounding which measures the time a pulse of sound to go to the ocean floor and back to the ship. It is based on the echo- ranging behavior of bats.

Seeing By Sonar oSpeed of sound in sea water travels about 1,520 meters per second. So if the sound makes a round trip of 2 seconds then it has traveled 1,520 meters down and 1,520 meters up. oExample: Imagine a sound pulse makes a round trip in 10 seconds. 1.) 10 / 2 = 5 seconds 2.) 5 x 1,520 = 7,600 meters