Seismographic Networks

Seismic recording systems monitor the ground movements continuously and we have records of the motion of the ground at some places dating back nearly 100 years. Seismographs were deployed in Japan, Italy and several other European countries in the late 1800's.  Caltech, UC Berkeley have long histories of monitoring California seismic activity. Saint Louis University also has records going back to the first few decades of the 1900's.

International monitoring of earthquakes also has a long history.  Global networks of seismometers were deployed early in the 1900's by the British Geological Survey and Jesuit institutions.  The WWSSN (World-Wide Standardized Seismographic Network) that was deployed by the U.S. (in cooperation with many other countries) in the 1960's to monitor nuclear explosions and to help verify nuclear test treaties established the 1960's. Today's global seismic network is a federation of cooperative, international effort that consists of  several hundred seismic recording stations that are part of several international efforts and many national efforts.

The place to go for information on seismic networks and stations is the International Federation of Digital Seismograph Networks (FDSN). The FDSN web address is A great place to find information, or meta-data, available on these networks is

The animation below shows the recent history of seismic networks that are available through the IRIS data management center - many other stations exist or existed in regions such as Japan, China, etc.