Wind & Rain

Wind and waves continue to break up the oil slick, which can eventually result in tarballs. Tarballs are small, dark globs of oil. Most tarballs are small, about the size of a coin. However, they can be as large as several inches across.

In a marine environment, tarballs are persistent and can travel hundreds of miles due to wind and current. So, the spread of tarballs and the oil slick in general depends on factors such as wind patterns, sea currents, proximity of the spill to land, temperature, marine traffic, as well as other conditions.

The crude oil's physical characteristics can start to change and the oil breaks down, through a process called "weathering." Chemical and biological (bacteria or microorganism) changes contribute to weathering, further changing the appearance of the oil.

Eventually, weathering will create a tarball with a hard, crusty outside and sticky inside. Particulates and sediments in the water or shoreline can adhere to tarballs.

Temperature can have an important effect on the stickiness of tarballs and crude oil in general. An increase in air or water temperature can cause tarballs or the oil slick to become more fluid, and thus more sticky.

Forces in the water or activity on the beach (people or animals moving around the beach) can cause tarballs to break open and expose softer, fluid centers. This leaking oil can then pose a hazard to any person or animal that comes into contact with it.

To learn more about Crude Oil Hazards visit our Crude Oil Hazards Online Training web page.