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What is the NCEDC?

Volume of Data Archived at the NCEDC by Data Type
Data Type GBytes
BDSN/NHFN/mPBO (broadband, electric and magnetic field, strain) waveforms 8,203
NCSN seismograms 30,118
Parkfield HRSN seismograms 3,877
GPS (RINEX and raw data) 2,933
UNR Nevada seismograms 1,580
SCSN seismograms 2,791
Calpine/Unocal Geysers region seismograms 38
EarthScope SAFOD seismograms 2,119
EarthScope USArray seismograms 281
EarthScope PBO strain and seismic waveforms 2,949
PG&E seismograms 688
USGS low frequency geophysical waveforms 3
Misc data 3,245
Total size of archived data 58,825

The Northern California Earthquake Data Center (NCEDC) is a permanent archive and distribution center primarily for multiple types of digital data relating to earthquakes in central and northern California. The NCEDC is located at the Berkeley Seismological Laboratory, and has been accessible to users via the Internet since mid-1992. The NCEDC was formed as a joint project of the Berkeley Seismological Laboratory (BSL) and the U.S. Geological Survey (USGS) at Menlo Park in 1991, and current USGS funding is provided under a cooperative agreement for seismic network operations.

Time series data come from broadband, short period, and strong motion seismic sensors, and geophysical sensors such as electromagnetic sensors, strain meters, creep meters, pore pressure, water level, and wind speed sensors. Earthquake catalogs can include time, hypocenter, magnitude, moment tensor, mechanisms, phase arrivals, codas, and amplitude data. GPS data are available in both raw observables and RINEX formatted data.

The NCEDC also provides support for earthquake processing and archiving activities of the Northern California Earthquake Management Center (NCEMC), a component of the California Integrated Seismic Network (CISN). The CISN is the California regional organization of the Advanced National Seismic System (ANSS).

Douglas Neuhauser is the manager of the NCEDC. Stephane Zuzlewski, Mario Aranha, Taka'aki Taira, Jennifer Taggart, Clay Miller, and Peggy Hellweg of the BSL and Lind Gee, Hal Macbeth, Lynn Dietz, and Fred Klein of the USGS Menlo Park contribute to the operation of the NCEDC.

If you use data from the NCEDC, we ask that you acknowledge the data center and the organizations that contributed the data.

We encourage you to contact us with questions, comments and feedback concerning the NCEDC. You can reach us vis email at or fill out our comments form.