Introduction to the Canadian National Seismograph Network

Natural Resources Canada (NRCan) operates a Canada-wide network of approximately 150 seismic stations that make up the Canadian National Seismograph Network (CNSN). More than 100 of these stations are equipped with both weak-motion seismometers and strong motion accelerometers, while the remainder have only weak-motion seismometers. The weak-motion seismometers record minute ground motions, such as from earthquakes that are small and/or distant. Strong-motion accelerometers are capable of recording stronger ground motions, from large, nearby earthquakes likely to cause damage.

NRCan operates, separately, a network of over 300 specialised sensors used by the Earthquake Early Warning system.

The continuous data stream from the Canadian National Seismograph Network is acquired and analysed in real time. This analysis includes the automatic detection, by each station, of possible signals from earthquakes. All this information is combined to calculate a location and magnitude for an earthquake. While the automatic results are not always accurate, and should be reviewed by an experienced analyst, they significantly reduce the time it takes to respond to a felt and/or damaging earthquake. Emergency planning and disaster relief agencies are more rapidly informed, and information is provided earlier to the general public. The network's high quality digital data is also used to conduct research on the properties of earthquakes. These results can be combined with information on the distribution, size and frequency of events to improve the earthquake-resistance provisions of the National Building Code.

For information about the type of data produced by CNSN stations as well as instrumentation, channels recorded, sample rates, sensitivities, and dates of operation, see the CNSN Station Book.