| Title | Earthquakes in the eastern Canadian Arctic: past occurrences, present hazard and future risk |
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| Author | Lamontagne, M ;
Bent, A |
| Source | Seismological Research Letters 2021 p. 1-14, https://doi.org/10.1785/0220210014 |
| Image |  |
| Year | 2021 |
| Alt Series | Natural Resources Canada, Contribution Series 20200722 |
| Publisher | Seismological Society of America |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Nunavut |
| Lat/Long WENS | -120.0000 -60.0000 85.0000 55.0000 |
| Subjects | tectonics; Science and Technology; arctic geology; earthquakes; earthquake magnitudes; seismology; seismic zones; climate, arctic; Canadian Arctic Archipelago |
| Illustrations | location maps; tables; plots |
| Program | Public
Safety Geoscience Intraplate Earthquakes |
| Released | 2021 05 05 |
| Abstract | 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. |
| Summary | (Plain Language Summary, not published)
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. |
| GEOSCAN ID | 328043 |
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