Macroseismic information for the seven largest moderate earthquakes of the Charlevoix seismic zone, Quebec, between 1870 and 2021: February 3, 1902, M 4.5; September 30, 1924, M 5.2; January 08, 1931, M 4.9; October 19, 1939, M 5.3; October 14, 1952, M 4.5; August 19, 1979, M 4.8; March 6, 2005, M 4.7

Abstract

This Open File Report provides the available macroseismic information for the seven largest moderate earthquakes that occurred in the Charlevoix Seismic Zone between 1870 and 2021. These earthquakes and their moment magnitude (M) are: 1) February 3, 1902, M 4.5; 2) September 30, 1924, M 5.2; 3) January 08, 1931, M 4.9; 4) October 19, 1939, M 5.3; 5) October 14, 1952, M 4.5; 6) August 19, 1979, M 4.8; 7) March 6, 2005, M 4.7. Five, possibly six, of these seven earthquakes occurred in the northeast portion of the CSZ, where the largest event of the period, the 1925 M 6.2 earthquake, also occurred. For each locality where the earthquakes were felt, macroseismic information is given and interpreted on the Modified Mercalli Intensity Scale. The original mail questionnaires filled by postmasters for earthquakes no. 3, 4, 5 and 6 are lost. Consequently, the main sources of information are the newspaper accounts except for no. 7 for which web-based questionnaires are available. The macroseismic information from localities in Canada and in the US (from NOAA) are tabulated in Microsoft Excel spreadsheets. Most newspaper clippings that have macroseismic information are included. The Open File also provides Google Earth kmz files that allow the felt information reports to be viewed in a spatial tool.