| Title | Assessment of ground motion models for use in southwest British Columbia |
| |
| Author | Brillon, C; Allen, T |
| Source | 11th Canadian Conference on Earthquake Engineering, abstracts; Canadian Association for Earthquake Engineering Newsletter 2015 p. 1-10 |
| Image |  |
| Year | 2015 |
| Alt Series | Earth Sciences Sector, Contribution Series 20150237 |
| Publisher | Canadian Association for Earthquake Engineering |
| Meeting | 11th Canadian Conference on Earthquake Engineering; Victoria, BC; CA; July 21-24, 2015 |
| Document | book |
| Lang. | English |
| Media | paper |
| File format | pdf |
| Province | British Columbia; Western offshore region |
| NTS | 92; 102 |
| Area | Vancouver Island |
| Lat/Long WENS | -131.0000 -121.5000 51.7500 48.0000 |
| Subjects | geophysics; tectonics; modelling; earthquakes; faults; Cascadia Subduction Zone; Explorer plate; Nootka Fault Zone; Revere-Delwood-Wilson Fault; Pacific plate; North American plate; Juan de Fuca
plate |
| Program | Public Safety Geoscience Western Canada Geohazards Project |
| Released | 2015 01 01 |
| Abstract | Southwest British Columbia (SWBC) is home to a complex tectonic regime that hosts frequent earthquakes. Natural Resources Canada is mandated to develop National Seismic Hazard Models, which underpin the
seismic provisions of the National Building Code of Canada. The production of these models requires assumptions on the use of Ground Motion Models (GMMs), often with little empirical evidence to guide the selection of appropriate GMMs. The high
seismic risk in SWBC warrants a regular validation of recorded ground-motions to those predicted by the GMMs that are currently used in seismic hazard assessments for this region, as well as those GMMs developed for global tectonic analogues. For
earthquakes occurring in SWBC between 1996 and 2015 with moment magnitude MW?5.0, ground-motion data from the Canadian National Seismic Network and the BC Ministry of Transportation and Infrastructure Internet Accelerometer network were extracted for
analysis. Pseudo spectral accelerations at 5% damping are calculated, binned (by distance and magnitude) and quantitatively compared to a number of modern GMMs to assess the suitability of each model for evaluating seismic hazard in SWBC. For the
shallow, offshore earthquakes assessed in this study, ground-motions are generally overestimated. The offshore and crustal GMMs of Atkinson and Adams (2013) implemented in Canada's most recent seismic hazard model, appear to be more suitable for
larger events (MW 6+) occurring in the North American continental crust. |
| Summary | (Plain Language Summary, not published)
Southwest British Columbia (SWBC) is home to a complex tectonic regime that hosts frequent earthquakes. The amount of ground-motion that can occur in an
area following an earthquake is estimated by ground-motion models (GMMs) which can be developed from recorded ground-motions of historic earthquakes. These estimates are used to develop National Seismic Hazard Models, which are used in the National
Building Code of Canada. For earthquakes greater than magnitude 5 occurring in SWBC between 1996 and 2015, data from the Canadian National Seismic Network and the BC Ministry of Transportation and Infrastructure Internet Accelerometer network were
included in this assessment. Ground-motions recorded at each of these stations were compared to those estimated by a number of modern GMMs. For the shallow, offshore earthquakes assessed in this study, ground-motions are generally overestimated. The
GMMs implemented in Canada¿s most recent seismic hazard model appear to be more suitable for larger events (greater than magnitude 6) that occur within 150 km offshore Vancouver Island. |
| GEOSCAN ID | 296959 |
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