Features of the Ocean Features of the Ocean FloorFloor

Exploration Time LineExploration Time Line

1915Scientists aboard the German ship

named Meteor used sonar to map the ocean floor. They used a device called the echo sounder to produce pulses of sound. The crew then timed the return of the echoes.

German Ship MeteorGerman Ship Meteor

Exploration time lineExploration time line

1943Jacques Cousteau and Emile Gagnan

invented SCUBA, which stands for “SSelf CContained UUnderwater BBreathing AApparatus”. A tank containing compressed air is strapped to the diver’s back and connected by a tube to a mouthpiece. SCUBA enables divers to explore to a depth of 40 meters.

First SCUBA gear 1943First SCUBA gear 1943

Exploration time line Exploration time line

1960 submersiblesVehicles with very thick metal hulls protect

explorers from extreme pressure and temperature, while enabling them to directly observe the ocean depths.

AlvinAlvin was the was the first deep-sea submersiblefirst deep-sea submersible capable of carrying passengers, usually a capable of carrying passengers, usually a pilot and two observers. Its first untethered pilot and two observers. Its first untethered dive measured 35 ft. Now, after numerous dive measured 35 ft. Now, after numerous upgrades and reconstructions, Alvin can upgrades and reconstructions, Alvin can plunge to a maximum depth of 14,764 ftplunge to a maximum depth of 14,764 ft..

Exploration Time Line Exploration Time Line

1978 Satellites1978 SatellitesSeasat A was the first satellite in Earth’s

orbit to study the oceans. Since satellites make millions of observations a day, they provide data on rapidly changing and widespread ocean conditions. Such data include temperatures, algae growth patterns, and even the movement of large schools of fish.

Specific objectives were to collect data on Specific objectives were to collect data on sea-surface winds, sea-surface temperatures, sea-surface winds, sea-surface temperatures, wave heights, internal waves, atmospheric wave heights, internal waves, atmospheric water, sea ice features and ocean topographywater, sea ice features and ocean topography

Features of the Ocean FloorFeatures of the Ocean Floor

Continental shelf: a gently sloping, shallow area of the Continental shelf: a gently sloping, shallow area of the ocean floorocean floor

1. The actual boundary of a continent is not its coastline, but the edge of the continental shelf.

2. Most continental shelves are broad, gently sloping plains covered by relatively shallow water.

3. Water depth over the continental shelves averages about 60 meters (200 feet).

4. Sunlight penetrates the shallow waters, and many kinds of organisms flourish—from microscopic shrimp to giant seaweed called kelp.

5. Ocean currents and runoff from rivers bring nutrients to organisms that live on continental shelves

SeamountsSeamounts

Mountains that are completely underwater. Seamounts - undersea mountains formed by

volcanic activity - were once thought to be little more than hazards to submarine navigation.

Today, scientists recognize these structures as biological hotspots that support a dazzling array of marine life.

The biological richness of seamount habitats results from the shape of these undersea mountains.

Thanks to the steep slopes of seamounts, nutrients are carried upwards from the depths of the oceans toward the sunlit surface, providing food for creatures ranging from corals to fish to crustaceans.

Abyssal PlainAbyssal Plain

A broad area covered with thick layers of mud and silt.

The plains are largest and most common in the Atlantic Ocean. They are less common in the Indian Ocean, and even more rare in the Pacific.

Mid-Ocean RidgeMid-Ocean Ridge

A continuous range of mountains that winds around Earth, much as the line of stitches winds around a baseball.

At the top of the mid-ocean ridge, about 2 kilometers above the abyssal plain, but still 1 kilometer below the surface.

It consists of two parallel chains of mountains separated by a central valley.

Sonar Sonar

SSound NNavigation aand RRanging, is a system that uses sound waves to calculate the distance to an object.

The sonar equipment on a ship sends out

pulses of sound that bounce off the ocean floor.

The equipment then measures how quickly the sound waves return to the ship.

Sound waves take longer to return if the ocean floor is farther away.