Seep
From Wikipedia, the free encyclopedia
A seep is a wet place where a liquid, usually groundwater, has oozed from the ground to the surface. Seeps are usually not flowing, with the liquid sourced only from underground.
The term seep may also refer to the movement of liquid hydrocarbons to the surface through fractures and fissures in the rock and between geological layers. Oil seeps are quite common: California has thousands of them. Much of the oil discovered in California during the 19th century was from observations of seeps.
Seeps may be a significant source of pollution.
Contents |
[edit] Coal Oil Point Seep Field
One seep, the Coal Oil Point Seep Field offshore from Santa Barbara, California has a seep area of about three square kilometers, and releases about 40 tons per day of methane and about 19 tons of reactive organic gas (ethane, propane, butane and higher hydrocarbons), which is about the same as that released by all the cars and trucks in the county. The liquid petroleum produces a slick that is many kilometers long and when degraded by evaporation and weathering, produces tar balls which wash up on the beaches for miles around.
This seep also releases on the order of 100 to 150 barrels of liquid petroleum per day. Hornafius et al. The Monterey formation contains about one billion barrels, so at the current leaking rate, it would be emptied of liquid petroleum in about 20,000 years if it were not being replenished. The estimated lifetime of the gas component is even shorter. The field produces about 9 cubic meters of gas per barrel of oil, and so there is about 9,000,000 cubic meters of gas in the reservoir. Hornafius et al. The seep would deplete this amount of gas in about 150 years.
[edit] See also
[edit] References
- Hornafius, J.S.Quigley, D.C., and Luyendyk, B.P. "The world's most spectacular marine hydrocarbon seeps (Coal Oil Point, Santa Barbara Channel, California): Quantification of Emissions", Journal of Geophysical Research, v.104, n. C9, pp. 20,703-20,711, September 15, 1999. [1]
[edit] External links
- Natural Oil and Gas Seeps in California
- Hyrdocarbon Seeps This UCSB site has a collection of papers describing a major seep just offshore from Santa Barbara, California.
