Coal Oil Point seep field (COP) info chemical Man

The Coal Oil Point seep field (COP) in the Santa Barbara Channel offshore from Goleta, California, is a marine petroleum seep area of about three square kilometres, within the Offshore South Ellwood Oil Field and stretching from the coastline southward more than three kilometers (1.9 mi). Major seeps are located in water depths from 20 to 80 meters. The seep field is among the largest and best studied areas of active marine seepage in the world. These perennial and continuous oil and gas seeps have been active on the northern edge of the Santa Barbara Channel for at least 500,000 years. The combined seeps in the field release about 40 tons of methane per day and about 19 tons of reactive organic gas (ethane, propane, butane and higher hydrocarbons); about twice the hydrocarbon air pollution released by all the cars and trucks in Santa Barbara County in 1990. The liquid petroleum produces a slick that is many kilometres 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 (16 to 24 m3) of liquid petroleum per day. The field produces about 9 cubic meters of natural gas per barrel of petroleum

Leakage from the natural seeps near Platform Holly, the production platform for the South Ellwood Offshore oilfield, has decreased substantially, probably from the decrease in reservoir pressure due to the oil and gas produced at the platform.