California Volcano Observatory

Monitoring Seismicity at California Volcanoes Requires Coordinated Plans

Detection and location of earthquakes via seismic networks has been a mainstay of California volcano monitoring plans since the 1970s.

Webicorder record from the 24-hours at the MEM

Webicorder record from the 24-hours at the MEM seismometer station in Long Valley Caldera shows occasional small earthquakes and diurnal noise. (Public domain.)

Seismicity at California volcanoes is monitored in partnership between multiple agencies that collaborate to form the California Integrated Seismic Network (CISN). There is significant variability in the number of stations at each volcano, which reflects the degree of difficulty in operating seismic stations in remote locations, proximity to population centers, recency of eruptive activity or unrest, and land-use permitting restrictions.