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Geography in the News: Oil Spills

By Neal Lineback and Mandy Lineback Gritzner, Geography in the NewsTM World’s Largest Oil Spills The world has followed news of British Petroleum’s (BP) Deepwater Horizon’s blowout and oil spill in the Gulf of Mexico since the oil rig exploded April 22, 2010. By the time engineers temporarily capped the well July 15, it had...

By Neal Lineback and Mandy Lineback Gritzner, Geography in the NewsTM

World’s Largest Oil Spills

The world has followed news of British Petroleum’s (BP) Deepwater Horizon’s blowout and oil spill in the Gulf of Mexico since the oil rig exploded April 22, 2010. By the time engineers temporarily capped the well July 15, it had poured an estimated 3.0 million to 8.7 million barrels of oil into Gulf waters. How does the magnitude of this spill compare with past oil spills?

This article only compares the magnitude of the world’s largest oil spills and does not compare damages. No oil spill is without environmental consequences. Those in ecologically sensitive areas, however, may carry particularly long-lasting environmental and economic impacts.

Although there are some differences in estimates of individual oil spills, since 1910, there have been at least 17 oil spills around the world exceeding 30 million U.S. gallons or 715,000 barrels. One barrel of oil equals 42 U.S. gallons.

Map by Geography in the NewsTM

Unless it derives from a ship disaster, oil spill magnitude is usually difficult to estimate. The volume of oil carried by a ship is always known. Most spills on land are easier to estimate than those that occur underwater from oil well blowouts.

The Deepwater Horizon’s spill in the Gulf of Mexico was apparently the second largest ever to occur. California’s legendary oil spill from a well blowout in Kern County in 1911 may have dumped an incredible 9 million barrels, according to the Los Angeles Times (June 13, 2010), making it the largest spill ever. The purposeful release of oil by the Iraqi army during Desert Storm in 1991 may have dumped two million to six million barrels into the Persian Gulf, probably making it the third largest.

Of the 17 largest spills ever, 10 were from ship groundings, collisions or explosions, four were from oil derrick or platform disasters, two were from pipeline leaks, and one was the purposeful release in Iraq.

The 104 worst spills in the world tend to concentrate in two types of locations. Petroleum source areas tend to have a high incidence of spills, generally associated with blowouts, explosions and trans-shipping accidents. These regions of the world include the Persian Gulf and the Gulf of Mexico, where well drilling is prevalent.

The other common spill location is along international oil trade routes, particularly in the North Atlantic, around Europe, East Asia and around Africa’s Cape of Good Hope. These areas are particularly susceptible to ship collisions and breakups. Furthermore, storms often contribute to these shipping disasters.

The remaining spills are more random and are usually linked to aging or failed equipment (pipeline breaks), natural hazards (hurricanes and floods) or human error (Exxon Valdez).

Of the spill disasters on or near U.S. territory, the most significant are the 1911California spill, the BP Deepwater spill and the Greenpoint oil spill in Brooklyn that occurred from the 1940s to 1950s (400,000 to 700,000 barrels) from a crude oil processing plant. The 1989 Exxon Valdez ship spilled approximately 260,000 barrels of oil in Prince William Sound in Alaska, ranking it the fourth largest in the United States and the 36th largest in the world. Despite the intense damage done to the ecosystem around Prince William Sound, the size of the spill does not compare with the world’s 17 largest.

The United States has sustained 47 documented oil spills, the largest number of any country in the world. The high incidence of spills is linked to the country’s high oil consumption.  The U.S. uses nearly one-quarter of the world’s oil. This high rate of consumption requires the handling and transfer of huge amounts of oil daily, making the chances of spills more probable.

Louisiana has sustained 14 significant oil spills, the largest of any state, followed by California (8), Pennsylvania (4), Texas (3) and Alaska (3). These are states with large transfers of petroleum between pipelines and ships.

Drilling and transporting technologies have made major advances in the past 40 years, but improvements in spillage and cleanup technologies apparently have not.

The Deepwater disaster in the Gulf of Mexico was a wake-up call for both the petroleum industry and government agencies that oversee the industry. Lessons learned from this oil spill are yielding more safeguards and new technologies for the future. The environmental, human and monetary costs of the spill remain high and long lasting to the Gulf Coast.

And that is Geography in the NewsTM

Sources: GITN 1055 World’s Biggest Oil Spills, Aug. 20, 2013;;; and

Co-authors are Neal Lineback, Appalachian State University Professor Emeritus of Geography, and Geographer Mandy Lineback Gritzner. University News Director Jane Nicholson serves as technical editor. Geography in the NewsTM  is solely owned and operated by Neal Lineback for the purpose of providing geographic education to readers worldwide.

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Meet the Author

Neal Lineback
Neal Lineback has written weekly Geography in the News (GITN) articles for more than 25 years (1,200 published articles) while he was Chair of Geography and Planning at Appalachian State University and since. In 2007, he brought his daughter Mandy Gritzner in as a co-author. She is also a geographer with a graduate degree from Montana State University. GITN has won national recognition and numerous awards from the Association of American Geographers, the National Council for Geographic Education and Travelocity, among others..