Major Oil spills since 1967. 1989

1989

March 24, Prince William Sound, Alaska: tanker Exxon Valdez hit an undersea reef and spilled 10 million–plus gallons of oil into the water, causing the worst oil spill in U.S. history.

Dec. 19, off Las Palmas, the Canary Islands: explosion in Iranian supertanker, the Kharg-5, caused 19 million gallons of crude oil to spill into Atlantic Ocean about 400 mi north of Las Palmas, forming a 100-square-mile oil slick.