| Title | North Coast geohazards - 2016 seismology update |
| Download | Downloads |
| |
| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Brillon, C |
| Source | Geological Survey of Canada, Open File 8052, 2016, 15 pages, https://doi.org/10.4095/298753  Open Access |
| Image |  |
| Year | 2016 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Media | on-line; digital |
| File format | pdf |
| Province | British Columbia |
| NTS | 93D; 93E; 93L; 103A; 103G; 103H; 103I; 103J |
| Area | Kitimat; Douglas Channel; Prince Rupert; Terrace; Bella Bella; Hartley Bay |
| Lat/Long WENS | -131.0000 -126.0000 55.0000 52.0000 |
| Subjects | geophysics; earthquakes; earthquake studies; earthquake mechanisms; amplitude spectra; seismic interpretations; seismic risk; seismic zones; seismic surveys; crustal studies |
| Illustrations | location maps; tables; histograms; plots |
| Program | Marine Geohazards Mapping & Monitoring (MGMM) |
| Released | 2016 06 03 |
| Abstract | Within British Columbia's north coast, specifically between Prince Rupert and Bella Bella, from the western coastline to the eastern extent of the Coast Mountains, there has been minimal research to
understand earthquake hazards (Brillon, 2016). A more detailed understanding of where and how regional strain energy is being accumulated in the crust and the likelihood of damaging earthquakes in this area is necessary to estimate ground shaking and
other earthquake-related hazards. To improve the understanding of seismic hazard in the area, five monitoring stations consisting of seismic and GPS instrumentation were installed in August 2014. In addition, a soft soil seismograph to measure
effects of local site conditions was installed in Kitimat and improvements to older GPS and seismic stations in the region were carried out.
During the first winter of the deployment a number of the stations suffered significant weather-related
damages that resulted in long periods of station downtime. By June 2015 all the stations were repaired and reinforced to minimize damages the following winter. Aside from the stations located in Kitimat, the background noise levels are within the
Petersen high and low noise models (Peterson, 1993). The low seismic noise levels consistently allow earthquakes offshore Haida Gwaii with magnitudes less than M2.0 to be used in analysis. In addition to these events 145 earthquakes within the study
area have been located. Although a number of earthquakes have been located in the north coast, the locations do not identify any new seismically active areas. |
| Summary | (Plain Language Summary, not published)
Within the Coast Mountains between Prince Rupert and Bella Bella, there has been minimal research to understand local earthquake hazards. To reduce this
knowledge gap, in 2014 five earthquake monitoring stations were installed in the area, each consisting of a seismograph to record earthquakes and a GPS (global positioning system) pier, to record long term changes in earth's crust. In 2016 an
additional seismograph was installed, and three older GPS sites were refurbished. For the first nine months after stations installation weather-inflicted damages resulted in minimal data availability. Following station repairs and reinforcements
station downtime is near zero and noise levels are comparative to typical land stations. Since the installation of these stations approximately 145 earthquakes have been located in the study area, the smallest being magnitude 0.5, the largest is
magnitude 3.3. GPS analysis will be possible after a minimum of 2.5 years of data has been recorded. |
| GEOSCAN ID | 298753 |
|
|