Thursday, April 26, 2007

Structural deformation revealed on sea-floor image

As you've seen from previous posts on this blog (e.g., here, here, and here) I have a penchant for images of sea-floor bathymetry. Not only are they fascinating (and aesthetically pleasing) but they constantly remind of us of how much we don't know about our own planet surface (remember, 2/3 of the Earth's surface is under water). We have mapped the surface of Mars better than Earth!

A recent Deep Sea News post reminded me of a great web resource if you are interested in marine science. It is called SIMoN, which stands for Sanctuary Integrated Monitoring Network, is a portal for all things related to the Monterey Bay National Marine Sanctuary. Much of the site involves the biological and habitat aspects (it is a sanctuary after all) but there is also great stuff regarding the geology and geomorphology of the area.

The image below (see page on SIMoN here for all the details) is from an area offshore of the central California near Half Moon Bay (just south of San Francisco and north of Santa Cruz). This area is called Mavericks and is a popular surfing spot.

What is most striking is how nicely the structural deformation of Pliocene sedimentary rocks is shown with this image. Movement on the San Gregorio fault (a wholly owned subsidiary of the San Andreas) has produced this folding and the layered nature of the strata has resulted in the differential erosion and alternating ridges and 'valleys' seen on the bathymetry.

1 comment:

Thermochronic said...

That is an amazing image. It would be a great addition to the view from seal cove, a stop for some of the intro geology courses just south of half moon bay. When the tide is low you can seem a similar structure (albeit much smaller).