| Title | Further studies on the 1988 Mw 5.9 Saguenay, Quebec, earthquake sequence |
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| Author | Ma, S; Motazedian, D; Lamontagne, M |
| Source | Canadian Journal of Earth Sciences vol. 55, no. 10, 2018 p. 1115-1128, https://doi.org/10.1139/cjes-2017-0231  Open Access |
| Image |  |
| Year | 2018 |
| Alt Series | Natural Resources Canada, Contribution Series 20180435 |
| Publisher | Canadian Science Publishing |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf (Adobe® Reader®); html |
| Province | Quebec |
| NTS | 21K/13; 21L/09; 21L/10; 21L/11; 21L/12; 21L/13; 21L/14; 21L/15; 21L/16; 21M; 21N/03; 21N/04; 21N/05; 21N/06; 21N/11; 21N/12; 21N/13; 21N/14; 22C/03; 22C/04; 22C/05; 22C/06; 22C/11; 22C/12; 22C/13; 22C/14;
22D; 31I/09; 31I/16; 31P/01; 31P/02; 31P/07; 31P/08; 31P/09; 31P/10; 31P/15; 31P/16; 32A/01; 32A/08; 32A/09; 32A/16 |
| Area | Saguenay River; Saguenay; St. Lawrence River |
| Lat/Long WENS | -73.0000 -69.0000 49.0000 46.5000 |
| Subjects | geophysics; seismology; earthquakes; bedrock geology; structural features; grabens; faults; modelling; earthquake foci; seismic waves; seismological network; 1988 Mw 5.9 Saguenay Earthquake; Saguenay
Graben; Charlevoix Seismic Zone; Canadian National Seismograph Network |
| Illustrations | location maps; spectra; seismograms; models; focal mechanisms; tables; graphs; geoscientific sketch maps; cross-sections; 3-D diagrams; profiles |
| Program | Public Safety Geoscience Assessing Earthquake Geohazards |
| Released | 2018 05 07 |
| Abstract | Many small earthquakes occur annually in Eastern Canada, but moderate to strong earthquakes are infrequent. The 25 November 1988 Mw 5.9 Saguenay mainshock remains the largest earthquake in the last 80
years in eastern North America. In this article, some aspects of that earthquake sequence were re-analyzed using several modern methods. The regional depth-phase modeling procedure was used to refine the focal depths for the foreshock, the
aftershocks, and other MN >= 2.5 regional earthquakes. The hypocenters of 10 earthquakes were relocated using hypoDD. The spatial distribution of eight relocated hypocenters defines the rupture plane of the mainshock. The moment tensor for the
mainshock was retrieved using three-component long-period surface wave records at station HRV (Harvard seismograph station) with additional constraints from P-wave polarities. One nodal plane is conclusively identified to be close to the rupture
plane, and its strike is similar to the trend of the south wall of the Saguenay Graben. Based on the consistency between the strike of the nodal plane and the trend of the Graben, as well as the deep focal depth distribution, we suggest that the
Saguenay earthquake sequence is related to the reactivation of one of the faults of the Saguenay Graben. |
| Summary | (Plain Language Summary, not published)
Some aspects of The 25 November 1988 MW 5.9 Saguenay foreshock-mainshock-aftershock sequence were re-analyzed using several modern methods. It is
suggested that the Saguenay earthquake sequence is possibly related to the reactivation of the Saguenay Graben system. |
| GEOSCAN ID | 314534 |
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