title: Weathering and the fallout plume of heavy oil from strong petroleum seeps near Coal Oil Point, CA.
abstract: The Coal Oil Point (COP) seeps offshore Goleta, CA, are estimated to release 20-25 tons of oil daily, providing an ideal natural laboratory to investigate the fate of oil in the coastal ocean. To address the long-term fate of COP oil, we collected 15 sediment samples down current from the seeps and quantified petroleum content and individual biomarkers using traditional and comprehensive two-dimensional gas chromatography. Similarities in the distributions of hopane biomarkers link the oil in the sediments to fresh seep oil (n=5) and underlying reservoirs (n=3), although sediment oil is heavily weathered. The spatial distribution of oil forms a plume along the continental shelf that we suggest represents a chronic fallout pattern for heavy oil from the persistent surface slicks; average surface currents appear to modulate the distribution of the fallout over a period of 0.4-5 days. The extent of hydrocarbon loss is consistent for all sediments, indicating a common limit to oil weathering with contributions from evaporation, biodegradation, and dissolution. Considering the amount of oil and quantity of sediment impacted, we estimate a sediment oil burden of 0.3 x 10(12) to 3 x 10(12) g in the study area, equivalent to 8-80 spills of the Exxon Valdez accident of 1989.
authors: Department of Earth Science and Marine Science Institute, University of California, Santa Barbara, California 93106, USA.
authors: Christopher
authors: C
authors: Farwell
authors: Christopher M
authors: CM
authors: Reddy
authors: Emily
authors: E
authors: Peacock
authors: Robert K
authors: RK
authors: Nelson
authors: Libe
authors: L
authors: Washburn
authors: David L
authors: DL
authors: Valentine
mesh_terms: D015415:Biomarkers; D002140:California; D002849:Chromatography, Gas; D003031:Coal; D019015:Geologic Sediments / Q000737:chemistry; D006838:Hydrocarbons / Q000032:analysis; D013058:Mass Spectrometry; D009821:Oils / Q000737:chemistry*; D010578:Petroleum / Q000032:analysis*; D012623:Seawater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014887:Weather
chemical_list: D015415:Biomarkers; D003031:Coal; D006838:Hydrocarbons; D009821:Oils; D010578:Petroleum; D014874:Water Pollutants, Chemical