Starting the summer of 2001, the USGS installed several new deformation stations in the Bay Area as part of the prototype Plate Boundary Observatory (PBO) program. These stations, referred to as the Mini-Plate Boundary Observatory, expand an existing network of Bay Area sites instrumented to measure deformation within the seismically active zone of the tectonic plate boundary between the Pacific and North American plates. (Plate Boundary Diagram)

Deformation will be measured using borehole strainmeters, seismometers, tiltmeters, pore-pressure monitors, and GPS (Global Positioning System) receivers. Some of these instruments are installed at the surface, while others are cemeted to solid bedrock at depths between 400 and 800 feet down a borehole. They will provide the information needed to see geodetic strain, microearthquake activity, and deformation at depth. (Prospective Instrument Sites) (Installation Diagram)

Additional Mini-Plate Boundary Observatory Information

Mini-Plate PBO Fact Sheet (pdf format) (requires Adobe Acrobat reader)

Recent Data