Introduction to the Canadian National Seismograph Network

The Geological Survey of Canada (GSC) operates a Canada-wide network of over 100 high-gain instruments, called seismographs, and over 60 low-gain or strong motion seismographs called accelerographs, that together make up the Canadian National Seismograph Network (CNSN). The high-gain instruments are used to record weak ground motion from earthquakes that are small and/or distant. Low-gain accelerographs are used to record the strong ground shaking from larger earthquakes at nearby sites likely to cause damage.

The continuous data stream from the Canadian National Seismograph Network is acquired and analysed in near real time. This analysis includes the automatic detection of possible signals from earthquakes by each station. 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.