There are many ways to measure the severity of oil spills—from the volume spilled to the extent of environmental damage to the cost of clean-up and recovery. The following list describes the worst oil spills in history, judged by the amount of oil released into the environment.
By volume, the Exxon Valdez oil spill ranks around 35th, but it is considered an environmental disaster because the oil spill occurred in the pristine environment of Alaska's Prince William Sound and the oil fouled 1,100 miles of coastline. It's still not known where the BP Deepwater Horizon oil spill in the Gulf of Mexico will end up placing on this list.
1. Gulf War Oil Spill
Date: January 19, 1991
Location: Persian Gulf, Kuwait
Oil Spilled: 380 million-520 million gallons
The worst oil spill in world history wasn't the result of a tanker accident, a pipeline failure, or an offshore drilling catastrophe. It was an act of war. During the Gulf War, Iraqi forces attempted to stop a potential American troop landing by opening the valves at the Sea Island oil terminal in Kuwait and dumping oil from several tankers in the Persian Gulf. The oil the Iraqis released created an oil slick 4 inches thick that covered 4,000 square miles of ocean.
2. Lakeview Gusher
Date: March 1910-September 1911
Location: Kern Country, California
Oil Spilled: 378 million gallons
The worst accidential oil spill in U.S. and world history occurred in 1910, when a crew drilling for oil beneath California scrubland tapped into a high-pressure reservoir 2,200 feet below the surface. The resulting gusher destroyed the wooden derrick and cause a crater so large that no one could get close enough to make a serious attempt at stopping the geyser of oil that continued uncontrolled for approximately 18 months.
3. Ixtoc 1 Oil Spill
Date:June 3, 1979 through March 23, 1980
Location: Bay of Campeche, Mexico
Oil Spilled: 140 million gallons
A blowout occurred at an offshore oil well that Pemex, a state-owned Mexican oil company, was drilling in the Bay of Campeche, off the coast of Ciudad del Carmen in Mexico. The oil caught fire, the drilling rig collapsed, and oil gushed out of the damaged well at a rate of 10,000 to 30,000 barrels a day for more than nine months before workers succeeded in capping the well and stopping the leak.
4. Atlantic Empress/Aegean Captain Oil Spill
Date: July 19, 1979
Location: Off the coast of Trinidad and Tobago
Oil Spilled: 90 million gallons
On July 19, 1979, two oil tankers, the Atlantic Empress and the Aegean Captain, collided off the coast of Trinidad and Tobago during a tropical storm. The two ships, which were carrying about 500,000 tons (154 million gallons) of crude oil between them, caught fire on impact. Emergency crews extinguished the fire on the Aegean Captain and towed it to shore, but the fire on the Atlantic Empress continued to burn out of control. The damaged ship lost approximately 90 million gallons of oil—the record for a ship-related oil spill—before it exploded and sank on August 3, 1979.
5. Kolva River Oil Spill
Date: September 8, 1994
Location: Kolva River, Russia
Oil Spilled: 84 million gallons
A ruptured pipeline had been leaking for eight months, but the oil was contained by a dike. When the dike collapsed, millions of gallons of oil spilled into the Kolva River in the Russian Arctic.
6. Nowruz Oil Field Oil Spill
Date: February 10-September 18, 1983
Location: Persian Gulf, Iran
Oil Spilled: 80 million gallons
During the Iran-Iraq war, an oil tanker crashed into an offshore oil platform at the Nowruz Oil Field in the Persian Gulf. Fighting delayed efforts to stop the oil spill, which was dumping about 1,500 barrels of oil into the Persian Gulf each day. In March, Iraqi planes attacked the oil field, the damaged platform collapsed, and the oil slick caught fire. The Iranians finally managed to cap the well in September, an operation that claimed the lives of 11 people.
7. Castillo de Bellver Oil Spill
Date: August 6, 1983
Location: Saldanha Bay, South Africa
Oil Spilled: 79 million gallons
The Castillo de Bellver oil tanker caught fire about 70 miles northwest of Cape Town, South Africa, then drifted before finally breaking apart 25 miles off the coast, presenting South Africa with its worst-ever marine environmental disaster. The stern sank in deep water with approximately 31 million gallons of oil still aboard. The bow section was towed far away from the coast by Altatech, a marine services company, then scuttled and sunk in a controlled manner to minimize pollution.
8. Amoco Cadiz Oil Spill
Date: March 16-17, 1978
Location: Portsall, France
Oil Spilled: 69 million gallons
The oil supertanker Amoco Cadiz was caught in a violent winter storm that damaged its rudder, making it impossible for the crew to steer the ship. The captain sent out a distress signal and several ships responded, but nothing could stop the huge tanker from running aground. On March 17, the ship broke in two and spilled its entire cargo—69 million gallons of crude oil—into the English Channel.
9. ABT Summer Oil Spill
Date: May 28, 1991
Location: approximately 700 nautical miles off the coast of Angola
Oil Spilled: 51-81 million gallons
The ABT Summer, an oil tanker carrying 260,000 tons of oil, was en route from Iran to Rotterdam when it exploded and caught fire on May 28, 1991. After three days, the ship finally sank about 1,300 kilometers (more than 800 miles) off the coast of Angola. Because the accident occurred so far offshore, it was assumed that high seas would disperse the oil spill naturally. As a result, not much was done to clean up the oil.
10. M/T Haven Tanker Oil Spill
Date: April 11, 1991
Location: Genoa, Italy
Oil Spilled: 45 million gallons
On April 11, 1991, the M/T Haven was unloading a cargo of 230,000 tons of crude oil at the Multedo platform, about seven miles off the coast of Genoa, Italy. When something went wrong during a routine operation, the ship exploded and caught fire, killing six people and spilling oil into the Mediterranean Sea. Italian authorities attempted to tow the tanker closer to shore, to reduce the coastal area affected by the oil spill and to improve access to the wreck, but the ship broke in two and sank. For the next 12 years, the ship continued to pollute the Mediterranean coasts of Italy and France.
11. Odyssey and Ocean Odyssey Oil Spills
Date: November 10, 1988
Location: Off the East Coast of Canada
Oil Spilled: About 43 million gallons per spill
Two oil spills that occurred hundreds of miles off the east coast of Canada in autumn 1988 are often mistaken for each other. In September 1988, the Ocean Odyssey, an American-owned offshore drilling rig, exploded and dumped more than a million barrels (about 43 million gallons) of oil into the North Atlantic. One person was killed; 66 others were rescued. In November 2008, the Odyssey, a British-owned oil tanker, broke in two, caught fire and sank in heavy seas about 900 miles east of Newfoundland, spilling about a million barrels of oil. All 27 crew members were missing and presumed dead.