Skip Links

USGS - science for a changing world

Open-File Report 03-122

Cruise Summary For P-1-02-SC: Acoustic Imaging Of Natural Oil And Gas Seeps and Measurement of Dissolved Methane Concentration In Coastal Waters Near Pt. Conception, California

By Thomas D. Lorenson, Jennifer A. Dougherty, William Ussler III, and Charles K. Paull

Link to HTML version of reportAbstract

Water-column acoustic anomalies and methane concentrations were documented in coastal waters surrounding Pt. Conception, California, in March 2002. The purpose of this survey, supported by the Minerals Management Service, was to locate active oil and gas seeps in the area as a background for further studies to determine hydrocarbon flux, mainly oil, into the environment. Objectives in reaching this goal are to (1) document the locations and geochemically fingerprint natural seeps within the offshore southern Santa Maria Basin; (2) geochemically fingerprint coastal tar residues and potential sources, both onshore and offshore, in this region; (3) establish chemical correlations between offshore active seeps and coastal residues thus linking seep sources to oil residues; (4) measure the rate of natural seepage of individual seeps and attempt to assess regional natural oil and gas seepage rates; (5) attempt to predict transport pathways of oil from seep sources to the coastline and; (6) interpret the petroleum system history for the natural seeps. This survey, addressing objective 1, focused on the area from offshore Surf Beach to the north and Gaviota to the south in water depths ranging from 20 to 500m. In addition, nine stations were sampled outside this area to provide a regional context. Water-column methane concentrations were measured in water samples collected from the R/V Point Sur with Niskin bottles from various depths. A total of 724 water samples from 94 stations were collected.

First posted June 4, 2003

For additional information, contact:
Contact Information, Pacific Coastal and Marine Science Center
U.S. Geological Survey
Pacific Science Center
400 Natural Bridges Drive
Santa Cruz, CA 95060
http://walrus.wr.usgs.gov/

Part or all of this report is presented in Portable Document Format (PDF). For best results viewing and printing PDF documents, it is recommended that you download the documents to your computer and open them with Adobe Reader. PDF documents opened from your browser may not display or print as intended. Download the latest version of Adobe Reader, free of charge.


Suggested citation:

Lorenson, Thomas D., Dougherty, Jennifer A., Ussler, William, III, Paull, Charles K., 2003, Cruise Summary For P-1-02-SC: Acoustic Imaging Of Natural Oil And Gas Seeps and Measurement of Dissolved Methane Concentration In Coastal Waters Near Pt. Conception, California: U. S. Geological Survey Open-File Report 03-122, http://pubs.usgs.gov/of/2003/0122/.


Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://pubsdata.usgs.gov/pubs/of/2003/0122/index.html
Page Contact Information: GS Pubs Web Contact
Page Last Modified: Thursday, 03-Apr-2014 13:13:49 EDT