Southern California Seismic Network

About SCSN

The SCSN is the southern California portion of the California Integrated Seismic Network (CISN). The CISN is the region of the Advanced National Seismic System (ANSS) that represents the entire state of California.

Under various names, the Southern California Seismic Network (or SCSN) has been monitoring earthquakes in Southern California since the 1920s.

Currently, using seismometers at over 410 sites, we monitor ground motion from the US/Mexico border north to a line which passes approximately through San Luis Obispo and Big Pine. More than 150 monitored sites are imported from other seismic networks in Southern California, Northern California, Nevada and Mexico. Instrumentation includes simple short-period vertical stations, modern broad-band stations and accelerometers.

The Southern California Seismic Network is a co-operative project of Caltech and the US Geological Survey. The SCSN has benefited from numerous upgrade projects:

  • TERRAscope, funded by the L. K. Whittier and ARCO Foundations and NSF, provided the first 28 broadband and strong motion stations in the late 1980s and early 1990s.
  • The TriNet project, 1997 to 2002, funded by FEMA, California IES, USGS, and other partners, increased the number of broadband and strong motion stations to 155 and significantly improved the data communications and processing infrastructure.
  • In September of 2009, Caltech received an ARRA grant for $1,200,000 from USGS/ANSS with the purpose of upgrading the equipment for the ANSS seismic monitoring sites.
  • The ShakeAlert (or Earthquake Early Warning) project was initially funded through the US Geological Survey (USGS) and in early 2012, the Gordon and Betty Moore Foundation provided three years of new funding for EEW research and for its development along the US west coast.
  • In 2013, we were granted some Urban Areas Security Initiative (UASI) funding to enhance the EEW capabilities by the adding and improving stations as well as boosting our overall system, increasing its speed, redundancy and reliability.

See our Network page to see how the network has changed over time.

The California Integrated Seismic Network (CISN) project of Caltech, CGS, USGS, and U.C. Berkeley (2001 to present) provides funds for continued operation of the SCSN, improved robustness, and migration of operations toward statewide processing.

All data are recorded by computers at Caltech. Earthquakes are detected picked, located and assigned a magnitude in near-real time. Our data are archived and distributed to the research and general public by the Southern California Earthquake Data Center (SCEDC), which holds the complete data archives for SCSN/CISN from 1932 to present. The SCSN operates one IRIS/GSN station, PAS in Pasadena, California.

If you use SCSN data, please go to the Acknowledgment Policy page to view the proper way to cite the SCSN.