Amazing sea floor maps reveal California's offshore depths

Offshore-and-Onshore-Geology-and-Geomorphology,-Offshore-of-San-Francisco-Map-Area,-California
Offshore and Onshore Geology and Geomorphology Offshore of San Francisco

The California Seafloor Mapping Program is the most extensive of its kind, initiated in 2008 and bearing fruit in a series of beautiful maps.

The CSMP has collected bathymetry (underwater topography) and backscatter data (providing insight into the geologic makeup of the seafloor) that are being turned into habitat and geologic base maps for all of California's State Waters (mean high water line out to three nautical miles). Although the CSMP was originally developed to support the design and monitoring of marine reserves through the Marine Life Protection Act, accurate statewide mapping of the seafloor has also contributed significantly to these efforts

Betsy Mason reports on the sensational underwater geography that the maps reveal. It's not just pretty: it will save lives.

This kind of information is critical because the magnitude of an earthquake is determined by the length of a fault that ruptures. Longer faults are capable of bigger quakes. If two smaller faults that were thought to be separate are actually connected, they could potentially rupture together to cause a bigger earthquake than previously thought. Discoveries of that sort could even change the USGS's seismic hazard forecast for California.

cData Integration and Visualization, Offshore of San Francisco Map.

dartnellData Integration and Visualization, Offshore of San Francisco Map (detail)

detailAcoustic Backscatter, Offshore of San Francisco Map Area

benthichabitats
Benthic Habitats

tomalesMassive granitic seafloor outcrop extends north and west from Tomales Point.

seafloorcharacter
Benthic Habitats off Tomales Point

Check out California Seafloor Mapping Programthe rest of the maps, though be warned they are USDA Grade A CPU-roasting epic multilayer PDFs.