Oil from the Deepwater Horizon well remained visible on the Gulf of Mexico’s surface on July 11, 2010. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image the same day. An especially bright patch appears southeast of the Mississippi Delta, near the approximate location of the oil leak.
The oil owes its visibility to sunglint, which is the mirror-like reflection of the Sun off the water. Oil smooths the water surface, changing the way it reflects and absorbs light. Very close to where the Sun’s reflection would appear on a totally calm sea, oil-coated water usually looks brighter than surrounding oil-free water. Farther away from the Sun’s reflection, however, oil may sometimes make the water look darker, depending on the viewing perspective. On July 9, 2010, sunglint highlighted oil west of the Mississippi Delta, even though that oil is not apparent in this image.
References & Resources
- Gulf of Mexico Oil Spill Response, the official site of the Deepwater Horizon unified command.
- Current information about the extent of the oil slick is available from the Office of Response and Restoration at the National Oceanic and Atmosphere Administration.
- Information about the impact of the oil slick on wildlife is provided by the U.S. Fish and Wildlife Service.
NASA image courtesy MODIS Rapid Response Team. Caption by Michon Scott.
