AMOS, JOHN F. Earth Satellite Corporation, Rockville, MD; JAMES BROOKS and IAN MacDONALD, Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas

ABSTRACT: Satellite-Based Synthetic Aperature Radar Imaging of Natural Oil Seeps in the Northern Gulf of Mexico

As a participant in NASA's Earth Observations Commercialization Applications Program (EOCAP) and The Geosat Committee's Gulf Offshore Satellite Applications Project (GOSAP), Earth Satellite Corporation, with the assistance of Texas A&M, has been developing a satellite-based technique for detecting and mapping natural offshore hydrocarbon seeps. Initial findings from the Green Canyon and Mississippi Canyon deepwater (> 1,000 meters) areas of the Gulf of Mexico showed that small slicks generated by natural oil seepage can be detected on digitally enhanced multispectral (i.e., Landsat Thematic Mapper) and synthetic aperture radar images. Additional radar images from the ERS-1 satellite have been obtained over much of the northern Gulf study area.

Sea-truth observations, surface sampling, and examination of an extensive core archive confirm that slicks detected on the imagery are directly attributable to natural seepage. Other observable features include ships, wakes, oil spills, offshore structures, ocean swell, local wind and current patterns and sediment plumes.

Satellite-based seep detection surveys can be conducted at relatively low cost over broad regions of the continental shelf to focus expensive petroleum exploration campaigns. Such surveys could also be applied to: 1) establish local and regional environmental baselines prior to petroleum development activities; 2) derive volumetric estimates of hydrocarbon seepage to improve our understanding of the global carbon cycle and refine worldwide estimates of recoverable petroleum reserves; and 3) assess the influence of hydrocarbon seepage on global climate models.

AAPG Search and Discovery Article #90987©1993 AAPG Annual Convention, New Orleans, Louisiana, April 25-28, 1993.