GEOSCAN Search Results: Fastlink

GEOSCAN Menu


TitleImpacts of the October 2012 Magnitude 7.8 Earthquake near Haida Gwaii, Canada
AuthorBird, A L; Lamontagne, M
SourceBulletin of the Seismological Society of America vol. 105, no. 2B, 2015 p. 1178-1192, https://doi.org/10.1785/0120140167
Year2015
Alt SeriesEarth Sciences Sector, Contribution Series 20140086
PublisherSeismological Society of America
Documentserial
Lang.English
Mediapaper; on-line; digital
File formatpdf
ProvinceBritish Columbia; Western offshore region
NTS103B; 103C; 103F; 103G/13; 103J/04; 103K/01; 103K/02; 103K/03
AreaHaida Gwaii
Lat/Long WENS-134.0000 -130.2500 54.2500 51.5000
Subjectstectonics; geophysics; tectonic setting; tectonic environments; seismicity; earthquakes; earthquake studies; earthquake magnitudes; earthquake mechanisms; tsunami; landslides; deformation; Cascadia subduction zone; Queen Charlotte Fault
Illustrationslocation maps; photographs; plots; tables
ProgramWestern Canada Geohazards Project, Public Safety Geoscience
AbstractOn 27 October 2012, a magnitude (Mw) 7.8 earthquake occurred in the sparsely populated region of Haida Gwaii, British Columbia, Canada (formerly called the Queen Charlotte Islands). This was the second largest recorded earthquake in Canadian history. It was felt throughout British Columbia and as far away as the Yukon, Alberta, and Montana, roughly 1600 km from the epicenter. In some locations (notably on Haida Gwaii) the perceivable shaking lasted 1.5–2 min, with very strong shaking for about 30 s. Strong ground motions recorded at three locations in the region reached a maximum horizontal acceleration of 0.2g. Fortunately, this earthquake resulted in very limited damage partly because of the relatively large distance (more than 60 km) between population centers and the fault rupture and partly because of seismic resistance of the generally low, wood-frame construction found on the islands. We examine the various physical effects from the shaking (e.g., tsunami, landslides, building damage, loss of hot springs), cataloged by field crews and reported by the inhabitants of Haida Gwaii and the surrounding regions. These will serve as a guide toward the potential impact from future large earthquakes on the various Haida Gwaii communities.
Through a Community Decimal Intensity evaluation of people's accounts, it was revealed that, although intensities were close to expected near the source zone, regional intensities were lower than predicted by the conventional western North America theoretical relation.
Finally, the October 2012 earthquake may be used as a scenario event for moderate subduction earthquakes in other, more populated areas of British Columbia, Canada, and the world.
Summary(Plain Language Summary, not published)
On 27th October 2012, a magnitude 7.7 earthquake occurred in the sparsely populated region of Haida Gwaii, British Columbia. This was the second largest recorded earthquake in Canadian history and was felt as far away as the Yukon, Alberta and Montana. In close locations, the perceivable shaking lasted 1.5 - 2 minutes, with very strong shaking for about 30 seconds. We examine the various physical effects throughout the region (e.g., tsunami, landslides, building damage, loss of hot springs). In contrast with the relatively light building damage and few, minor injuries, many of the Haida Gwaii inhabitants found the earthquake sequence a traumatic experience. Through public outreach, we endeavoured to mitigate the earthquakes' psycho-social impacts; myths and misconceptions on earthquakes and tsunami had to be addressed directly. Finally, this earthquake may be used as a scenario event for moderate subduction earthquakes in other, more populated areas.
GEOSCAN ID294607