What is the Role of the Oceans in Earth's Systems?

What is the Role of the Oceans in Earth's Systems?

HMH Unit 6.3 Crash Course

Salty, Saltier, Saltiest

• You have learned that about 97% of the water on Earth is salty. The map below shows how saltiness, or salinity, can vary across the oceans.

• The Red Sea and the Mediterranean Sea have higher salinity, on average, than other parts of the ocean. These variations are relatively small, but can affect the movement of ocean water in big ways. 

What's at the Bottom of the Ocean?

• Like the land we walk on, the ocean floor also has interesting features.

• Around continents, there can be a relatively shallow area of ocean floor that extends many kilometers. This is called a continental shelf.

What's at the Bottom of the Ocean?

• The continental slope is the steep area where the ocean rapidly gets deeper.

• The continental rise is the lower part of the continental slope. It can reach 4,000 m (13,000 ft) below the ocean’s surface.

• In many parts of the ocean, there are long ridges of undersea mountains and volcanoes. These are called mid-ocean ridges.

What's at the Bottom of the Ocean?

• The abyssal plain is the relatively flat, deep, vast area of the ocean floor.

• A trench is a deep, valley-like part of the ocean floor, often near the edge of an island chain or continent.

Now that we know some about the ocean, how does it affect other areas?

Let's learn about some ways that scientist are trying to prevent costal erosion

What about ocean currents?