The northern shelf of the Santa Barbara basin exposes bedrock at several locations. Folded and faulted strata of the Upper Miocene Monterey and Sisquoc Formations crop out on the shelf south of Goleta (eastern portion of above figure), where there are also extensive active hydrocarbon seeps (Fischer and Berry, 1973; Quigley et al., 1999). The shelf edge between Santa Barbara and Gaviota follows the 85 m depth contour.
The EM300 30 kHz multibeam bathymetric data show that the northern flank of the Santa Barbara Basin has experienced massive slope failures. The most prominent feature is the 134-km2 compound slump and debris flow associated with the Goleta landslide located off Coal Oil Point near Goleta. The Goleta slide is 14.6-km long, and is 10.5 km wide, extending from 90 m to nearly 574 m depth. The Goleta landslide is composed of distinct western, central and eastern segments, suggestive of multiple failure events. Each segment contains a well-defined head scarp, down-dropped head block and a slide debris lobe. The debris lobes exhibit hummocky topography in their central areas that appear to result from compression during down slope movement. The toes of the western and eastern lobes are well defined in the multibeam image, whereas the toe of the central lobe is less distinct and presumably older.
Several other smaller (2 km2 to 4 km2 in area) slides are located on the northern flank of the Santa Barbara Basin, both to the west and east of Goleta slide. One located west of the Goleta slide, named the Gaviota slide by Edwards et al. (1995) and Hampton et al. (1996), is 3.8 km2 in area and measures 2.6 km long and 1.7 km wide. A distinct narrow scar extends from near the eastern head wall of this slide over 2 km eastward toward the Goleta slide and may represent either an incipient failure or a remnant of a previous failure.
Concepcion fan, described by Kraemer (1986) and Fischer and Cherven (1998), consists of four major braided channels that extend into the basin to a water depth of about 580 m. The fan system originates within three canyons that incised into the shelf edge south of Gaviota.
Perspective view from the west
|Index Map||Arguello Canyon||Santa Barbara Basin||Rodriguez Seamount|