2. Ocean Shapes Earth

The ocean has the power to build, shape, and break down the land, forming the earth as we know it today. It is the interaction between the ocean, also called the hydrosphere, and the land, known as the geosphere, that causes these changes on the earth.

Erosion plays a big part in shaping the earth. When tiny bits of rock, dirt, shells, and sometimes even pieces of animal bones break off from the land forms, they form what is called sediment. Erosion pulls these sediments along with the flow of water.

Eventually, sediment falls to the bottom of the ocean or is thrown up on land with the waves. These piles of sediment can collect at the edges of rivers or at the ocean's coast. This is where sand comes from. Sand is made up of tiny bits of rock, plants, minerals, and animals.

To see for yourself how water breaks down these solid forms, complete the Candy Erosion Experiment

Just as materials can be broken down to make sand, they can also be pushed together to form rock. There are 3 main types of rocks that are important to know:

Igneous Rock: is formed when magma (liquid rock) from underneath the earth's crust cools and hardens to form a rock.

Sedimentary Rock: is formed at the earths surface when fragments of rocks, minerals, and organisms are compacted and hardened together under pressure. Rather than staying in broken pieces like sand, these sediments fuse together to form rock.

Metamorphic rock: is formed when other types of rocks, like igneous or sedimentary rock, are fused together to form a new kind of rock.


Just as new rocks can be formed or broken down in the ocean, entire new land forms can also be created. Volcanoes are underwater mountains that release hot molten rock, or lava, from underneath the earth's crust. When these rocks harden, they can create new land forms called Islands. It is through this release of material from under the earth's crust at the bottom of the ocean that forms new rocks and materials. Complete Discovering New Land to earn a badge

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Now that you understand how the ocean shapes the earth, you are ready for the Quiz! Take the quiz HERE. Once you have completed the quiz, you may move on to the next section, Weather and Climate.


Continue to Candy Erosion Experiment »