Ocean Exploration and Sea Floor Characteristics 8 th Grade Earth Science

Ocean Exploration  Ships – People have used the oceans since ancient times. They have charted and mapped the oceans, currents, and tides mostly by studying the stars.  1925 – Sonar developed; use of echo sounding to determine the depth of the ocean floor.  1943 – SCUBA developed: Jacques Cousteau created a tank that allowed people to breathe underwater and stay submersed for much longer than ever before.

Ships, etc

Ocean Exploration  1960 – Submersibles: Scientists for the first time went to the bottom of the challenger deep (over 11 km deep).  1978 – Satellite Technology: Scientists could now use SEASAT to observe the oceans. The satellites can track depth, temperature, currents, weather, etc.  2003 – Deep Flight Aviator: New type of submersible that moves faster and has better views than ever before.

SEASAT

Submersibles:

Ocean Floor Features  Continental Shelf: Considered part of the continent itself, it’s the gently sloping part of the continent that begins to go underwater.  Continental Slope: Steeply sloping part of the continent that is completely underwater.  Abyssal Plain: Flat bottom of the ocean floor.

Ocean Floor Features  Mid-Ocean Ridge: Mountain range in the middle of the ocean; located where new ocean floor is being created by plate separation (located in Atlantic, not Pacific)  Trench: Deepest part of the ocean; formed where one plate goes under the other (located in Pacific, not the Atlantic)

Ocean Floor Features  Seamount: Isolated mountain (away from the ridge) that does not reach the surface.  Island: A seamount that is tall enough to reach the surface

Ocean Features Diagram

Atlantic Ocean Profile The Atlantic Ocean Seafloor The Atlantic Ocean Seafloor

Ocean Life

 Benthos: Bottom Dwellers – Animals or plants that inhabit the ocean floor (crabs, sea stars, lobsters, octopus)  Nekton: Swimmers – Animals that have the ability to swim from place to place (squid, most fish, whales, seals)  Plankton: Floaters – Animals or plants that depend on currents and waves (tiny young fish, diatoms, some jelly fish)

Benthos-Bottom Dwellers

Nekton-swimmers

Plankton-floaters

Relationship between organisms  Food Web: When one organism eats another organism that eats a plant  Example: Polar bear eats a seal which eats artic cod which eats silversides which eats algae.  The energy is passed from one organism to the next as they eat the objects.

OCEANFOOD WEBOCEANFOOD WEBOCEANFOOD WEBOCEANFOOD WEB

Ocean Habitats  The Intertidal Zone: the area on or near the beach between high tide and low tide.  The organisms that live there must be able to tolerate changes such as salinity and temperature, as well as periods of being underwater and out of the water. They also have to deal with pounding waves.  Examples: Crabs, sea stars, sea cucumbers, hermit crabs.

Intertidal Zone

Ocean Habitats  Neritic Zone: Extends from the low tide line out to the edge of the continental shelf.  This area is shallow and receives a steady supply of sunlight, so the water is warm and full of plant life which makes it bursting with animal life also!  This would be the area where a lot of fishing industries obtain their fish.

Neritic Zone

Ocean Habitats  The Open Ocean: begins at the end of the shelf and continues into the deep seas  This area receives less sunlight and fewer nutrients, so it supports fewer animals.  The animals that live here travel for miles for food supplies.  Examples: Whales, sharks and squid

Open Ocean

Water Column  Don’t forget that the water also differs as you go down into the ocean!  Top Layer = Mixed layer or Surface Zone  Middle Layer = Thermocline or Transition Zone  Bottom Layer = Deep water (zone)

Thermocline

Shore Zones  Sandy Shores: Flat land areas that contain beaches  A Beach is an area made up of broken rocks or shells near the shore line.  The color of the beach depends on the color of the rock being broken down. There are white sand, green sand, black sand, and of course the ugly tan New Jersey beaches!  New Jersey, Maryland, Carolinas, and Florida all have sandy shores.

Sandy beaches

Shore Zones  Rocky Shore Zone: Sometimes the waves of the ocean hit directly onto rocks; places where there are not any beaches.  Caves: are a big feature at these locations  Examples: Maine, Massachusetts, North and West Coast of the U.S.

Rocky Shores

Sea Caves

Questions 1) Identify the three categories of ocean organisms and describe their characteristics. 2) What are conditions like in the intertidal zone? 3) Describe the physical conditions in the Neritic Zone. 4) What are the two type of shore zones and give a specific location where each would be found.