A USGS project called the California Seafloor Mapping Program, ongoing since 2007, has just produced some pretty and highly detailed new maps of the seafloor of the San Francisco Bay and our immediate coastline, as Wired reports. The unprecedented effort has involved data collection through sonar, acoustic backscatter, seismic-reflection profiles, seafloor photos and video, all extending three miles out from the coast, and the maps are just now being released, beginning with maps of San Francisco and the Bay, Tomales Bay, and Drakes Bay.

Among other things, the maps help with modeling for coastal flooding dangers from sea-level rise and large storms, and with identifying offshore active faults and submarine landslides, "providing the basis for earthquake and tsunami hazard assessments and hazard mitigation."

Also, they're pretty! Did you know there was a deep trench right beneath the Golden Gate Bridge, deeper than anywhere else in the Bay or our immediate coast?

See the Tomales Bay bathymetry map below, and check out more here.


And this video shows a virtual flyover of the topography of the seafloor from the entrance to the Bay, up to Bolinas, and down to Pescadero.

Map via USGS