Remote Sensing Study of Historical Changes in Natural Oil Slick Volumes in the Santa Barbara Channel

J. Scepan, J. Estes, and J. S. Hornafius

Large natural oil slicks are continually forming in the Santa Barbara Channel as a result of natural hydrocarbon seeps that occur above subsurface oil accumulations. Evaporation of volatile constituents in these oil slicks is a significant source of air pollution. In this study we employed a suite of remote sensing data along with a variety of image processing and geographic information system techniques to analyze the location, extent and changes in sea surface oil slicks during the period of 1975 - present. An extensive collection of airborne and spaceborne remote sensor data was accessed and examined for this study, including aerial photography, airborne spectral and microwave data, Landsat MSS and TM data and Shuttle Imaging Radar. Areas of oil slick accumulations wer identified, delineated, georeferenced, measured and mapped to a common scale using both manual and digital techniques. A Gaussian mathematical model was employed to provide quantitative estimates of surface oil accumulations identified within each image over the entire twenty year period. This study indicates that variances in mapped oil slick location and extent as well as the estimated amounts of oil present within each image may be attributed to image type and quality as well as environmental conditions.

AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California