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Pacific Coastal and Marine Science Center

Natural Oil & Gas Seeps in California

Some Examples of Oil & Gas Seeps

There are many naturally-occurring oil and gas seeps in the state of California. Pictured below are some examples selected to portray the broad range in physical characteristics of seeps. The oil in some seeps is sticky and thick, like tar; in others it is dark and runny, like strong coffee; gas seeps are invisible but may be ignited with a match.

Photo of Santa Barbara asphaltum.The asphaltum in this seep near Santa Barbara, California, is so viscous that it has a ropy texture like lava from a volcano.

Photo by I. Priestaf. From Onshore Oil and Gas Seeps in California.

Photo of rock streaked with crude oil.This rock is streaked black by liquid crude oil that is trickling naturally out of the ground. This seep is located in Ventura County, California.

Photo by M. Dosch. From Onshore Oil and Gas Seeps in California.

Photo of natural gas seep.This natural gas seep in Humboldt County is used by local inhabitants to roast marshmallows. It emits a mixture of flammable hydrocarbon gases, including methane, ethane, and propane.

Photo by L. Magoon.


California Oil and Gas Seeps Home

The “Natural Oil and Gas Seeps in California” project is a collaborative between the USGS and the California Department of Conservation

See also:

Pacific Coastal and Marine Science Center

USGS Coastal and Marine Geology Program

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Page Last Modified: 19 January 2011 (lzt)