Science

Sea-Floor Sunday #2: Submarine landslide

Today’s bathymetric image is from Santa Barbara Basin, offshore southern California. Santa Barbara Basin has received a lot of mud (and very little sand) since the Last Glacial Maximum (~18,000 yrs ago), and therefore has a nice “smooth” look to it in the bathymetry. But, there is a prominent geomorphic feature that pops out. It […]

Today's bathymetric image is from Santa Barbara Basin, offshore southern California. Santa Barbara Basin has received a lot of mud (and very little sand) since the Last Glacial Maximum (~18,000 yrs ago), and therefore has a nice "smooth" look to it in the bathymetry. But, there is a prominent geomorphic feature that pops out. It is a submarine landslide scarp and deposit called the Goleta Slide. Click on the below image for a larger view.

sbb_goleta1.jpg

Here's a blurb from the Monterey Bay Aquarium Research Institution (MBARI) mapping program website:

The Goleta slide is a 134-km2 compound slump and debris flow off Coal Oil Point near Goleta. The 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.

Below is another image...this one a perspective image looking north-northeast. The headwall scarps along the continental shelf edge are clearly visible. This one is also worth clicking on for a larger and higher-resolution view.

sbb_goleta2.jpg

There have been numerous studies about Goleta slide...I don't have time right now to go into them in detail. This link will take you to Google Scholar with "goleta slide" in the search box.

These images were produced with a freeware application called GeoMapApp from the Marine Geoscience Data System. Sometimes it's a little bit clunky to use (not as slick as GoogleEarth), but is a good way to explore for high-res bathymetry data in a global database.

UPDATE: You may have found your way here through geology.com/news. Thanks to them for the link! If you want to see more sea-floor images, check these posts out.