| Titre | Earthquakes in the eastern Canadian Arctic: past occurrences, present hazard and future risk |
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| Auteur | Lamontagne, M ;
Bent, A |
| Source | Seismological Research Letters 2021 p. 1-14, https://doi.org/10.1785/0220210014 |
| Image |  |
| Année | 2021 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20200722 |
| Éditeur | Seismological Society of America |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1785/0220210014 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Nunavut |
| Lat/Long OENS | -120.0000 -60.0000 85.0000 55.0000 |
| Sujets | géologie de l'arctique; secousses séismiques; magnitudes des séismes; séismologie; zones sismiques; climat arctique; Archipel Arctique Canadien; tectonique; Sciences et technologie |
| Illustrations | cartes de localisation; tableaux; graphiques |
| Programme | Géoscience pour la sécurité publique Tremblements de terre intraplaques |
| Diffusé | 2021 05 05 |
| Résumé | (disponible en anglais seulement)
The Canadian Arctic encompasses several active seismic areas where a small number of significant earthquakes have been recorded since the early 20th century.
Our study area is defined as the eastern Canadian Arctic, an immense territory that covers 30% of the Canadian territory. It includes the territory of Nunavut and the region of Nunavik in northern Quebec. Ten earthquakes had a moment magnitude (M)
between 5.9 and 7.4, but only five can be considered significant because of their impact. Most were felt in communities at distances of a few hundreds of km, but none exceeded Modified Mercalli Intensity (MMI) V. This paper contains descriptions of
the impact of these five earthquakes and of smaller ones that were felt in nearby communities. These macroseismic effects suggest stronger attenuation of MMIs than what is generally assumed for eastern North America. According to the current seismic
zoning, very few communities face a significant earthquake hazard. Seismic risk has to consider that most high arctic buildings are built on piles sitting on permafrost. It is believed that the newer engineered constructions would resist fairly well
to seismic shaking. On the other hand, some buildings with older at grade foundations with little lateral resistance may not resist well to intense earthquake shaking. The fast warming of the arctic is believed to lead to thickening of the active
layer of the permafrost, which may increase the potential for slope instabilities during earthquake shaking. The change would not be significant enough to alter the potential for local ground-motion amplification. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Dix tremblements de terre dans l'est de l'Arctique canadien ont eu une magnitude du moment sismique (M) comprise entre 5,9 et 7,4, mais seuls
cinq peuvent être considérés comme importants en raison de leur impact. La plupart ont été ressentis dans des communautés situées à quelques centaines de km de distance, mais aucun n'a dépassé l'intensité de Mercalli modifiée (MMI) V. Ce document
contient des descriptions de l'impact de ces cinq tremblements de terre et de ceux, plus petits, qui ont été ressentis dans des communautés à proximité. Ces effets macroséismiques suggèrent une atténuation des MMI plus forte que ce qui est
généralement supposé pour l'est de l'Amérique du Nord. Selon le zonage sismique actuel, très peu de communautés sont confrontées à un aléa sismique important. |
| GEOSCAN ID | 328043 |
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