SUMMARY

Beaches are made up of sediments, which were deposited by the ocean. Sediments range from clay and mud, which are very fine-grained, to coarse-grained sand or gravel. This exercise, developed by NOAA, demonstrates how lighter and heavier oils behave differently when spilled onto fine-grained, medium-grained, and coarse-grained sediment.

In oil spill response, differences among oils in whether and how they penetrate into different sediments is important. These differences affect our predictions of whether the oil is likely to remain on the surface if it hits the beach, or to penetrate to some degree into the beach sediment. As you can imagine, it's much harder to clean up subsurface oil than oil that stays on the beach surface. When we expect spilled oil to penetrate into beach sediment, we know that it must be cleaned up as quickly as possible.

In this experiment, we use molasses to simulate a heavy oil, such as a fuel oil for ships, and mineral oil to simulate a lighter oil, such as a light crude or diesel oil.

CONTEXT FOR USE

Materials

• 3 wide-mouth containers
• measuring cup
• coarse-grained sand or gravel
• medium- to fine-grained sand
• clay or mud
• molasses
• mineral oil

ACTIVITY DESCRIPTION AND TEACHING MATERIALS

Sediment Penetration Exercise