The geophysical instruments operated at Parkfield by the USGS and its collaborators are designed to monitor tectonic processes leading up to the expected earthquake and to record the strong shaking and crustal deformation that will result from it. Because the anticipated earthquake is expected to resemble historic Parkfield earthquakes, especially the 1966 event, data from previous shocks were used to guide the design of the monitoring networks. For example, the rupture zone of the 1966 earthquake and the locations of the 1966 hypocenter and 1934 and 1966 foreshocks near the rupture zone's north end are areas of intense monitoring. Some monitoring efforts have been discontinued, but most are currently operating.

Summary Table Details on instruments and measurements Deformation Networks Creep, strain, tilt, GPS, EDM, tilt and water well levels. Summary Map Monitoring networks in the Parkfield area Electromagnetic Networks Magnetometers, magnetotelluric, ULF, resistivity and radio frequency emission Seismic Networks NCSN, HRSN, strong motion, accelerometer and GEOS Discontinued Monitoring Since the inception of the Experiment some monitoring has been discontinued.

Parkfield Network Summary Map

Monitoring networks in the Parkfield area. EDM: Electronic Distance Measuring System GEOS: General Earthquake Observation System GPS: Global Positioning System HRSN: High-resolution Seismic Network NCSN: Northern California Seismic Network ULF: Ultra-low frequency UPSAR: USGS Parkfield Dense Seismic Array