1. Essential Question:
How are the geological features that exist on land similar to the geological features on the ocean floor?

2. Geography of the Oceans
The world ocean can be divided into four main ocean basins—the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, and the Arctic Ocean.
The Pacific Ocean is the largest and has the greatest depth
The Atlantic Ocean is about half the size of the Pacific and not quite as deep.
The Indian Ocean, largely a southern hemisphere body, is slightly smaller than the Atlantic.
The Arctic Ocean is about 7 percent of the size of the Pacific.
Geography of the Oceans

3. Mapping the Ocean floor
The topography of the ocean floor is as diverse as that of the continents
Today’s technology—particularly sonar, satellites, and submersibles—allows scientists to study the ocean floor in a more efficient and precise manner than ever before.
Mapping the Ocean floor

4. Sonar is an acronym for sound navigation and ranging
Sonar is an acronym for sound navigation and ranging. It is also referred to as echo sounding.
Sonar works by transmitting sound waves toward the ocean bottom.
The sonar equipment on a ship sends out pulses of sound that bounces off the ocean floor
The equipment then measures how quickly the sound wave returns to the ships
Sonar

5. Satellites are able to measure small differences by bouncing microwaves off the ocean surface.
Using this new technology, scientists have discovered that the ocean surface is not perfectly flat.
Satellites

6. Submersibles are small underwater crafts used for deep-sea research
Today, many submersibles are unmanned and operated remotely by computers. These remotely operated vehicles (ROVs) can remain underwater for long periods.
Submersibles

7. Let’s go exploring… Lets journey to the bottom of the ocean floor!
As we leave the harbor, we make our way over a section of the ocean floor called the continental shelf…
Let’s go exploring…

8. A continental shelf is the gently sloping submerged surface extending from the shoreline.
Continental shelves contain important mineral deposits, large reservoirs of oil and natural gas, and huge sand and gravel deposits.
A continental slope is the steep gradient that leads to the deep-ocean floor and marks the seaward edge of the continental shelf.
A continental rise is the gently sloping surface at the base of the continental slope.
Shallow Water

10. Deep ocean basin, which is about 2. 5 to 3
Deep ocean basin, which is about 2.5 to 3.5 miles deep, covers 30 % of Earth's surface and has features, such as abyssal plains, deep-sea trenches and seamounts.
Abyssal Plains is the broad, flat area of the ocean floor with thick layers of mud and silt. It also contains thick layers of sediment, formed by the sunken remains of dead organisms form the surface.
Mid-Ocean Ridges are the mountain chains formed where tectonic plates pull parts
Rift Valley is the area between two tectonic plates that have moved apart
Open Ocean

11. Seamounts are mountains found below the ocean whose peaks have not reached the surface
Ocean Trench is seemingly bottomless cracks in the ocean floor found at subduction zones
Volcanic Island is a mountain on the ocean floor whose peak has reached above the water’s surface
Open Ocean