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Two-Dimensional Seismic Velocities and Structural Variations at Three British Columbia Hydro and Power Authority (BC Hydro) Dam Sites, Vancouver Island, British Columbia, Canada

Open-File Report 2019-1015
By: , , , , , and 
https://doi.org/10.3133/ofr20191015

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Summary

In June, 2017, we acquired seismic data along five linear profiles at three British Columbia Hydro and Power Authority (BC Hydro, a Canadian provincial Crown Corporation) dam sites (John Hart, Ladore, and Strathcona Dams) on Vancouver Island, British Columbia, Canada. We also attempted to acquire linear seismic profiles at two additional BC Hydro dam sites (Ruskin Dam and Stave Falls Dam) east of the City of Vancouver, British Columbia, Canada; however, due to a seismograph programming error, little active-source data from Ruskin Dam and Stave Falls Dam were recorded. Thus, results from Ruskin Dam and Stave Falls Dam are not included in this report. At the three dam sites with successful data acquisition, we acquired both active- and passive-source data. Data acquisition details for each of the three dam sites varied in terms of seismic sources, the number of seismographs, and profile length and orientation. However, for active-source acquisition at each dam site, we acquired one or more linear seismic profiles ranging in length from about 150 to 400 meters (m), and along each profile, seismograph spacing was either 3 m or 5 m (see appendix 1). All data were recorded in three components (vertical and two horizontals). To greatly increase the resolution of the seismic velocity structure along these profiles, we co-located active sources at each seismograph.

Suggested Citation

Catchings, R.D., Addo, K.O., Goldman, M.R., Chan, J.H., Sickler, R.R., and Criley, C.J., 2019, Two-dimensional seismic velocities and structural variations at three British Columbia Hydro and Power Authority (BC Hydro) dam sites, Vancouver Island, British Columbia, Canada: U.S. Geological Survey Open-File Report 2019–1015, 125 p., https://doi.org/10.3133/ofr20191015.

ISSN: 2331-1258 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Executive Summary
  • Introduction
  • Tectonic Setting and Geology
  • Seismic Surveys and Acquisition
  • Data
  • Active-Source Seismic Models
  • Ambient Noise Model
  • Local and Regional Variation in Velocities
  • VS Acquisition and Evaluation Methods
  • References Cited
  • Appendixes 1—4
Publication type Report
Publication Subtype USGS Numbered Series
Title Two-dimensional seismic velocities and structural variations at three British Columbia Hydro and Power Authority (BC Hydro) dam sites, Vancouver Island, British Columbia, Canada
Series title Open-File Report
Series number 2019-1015
DOI 10.3133/ofr20191015
Year Published 2019
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Earthquake Science Center
Description Report: ix, 125 p.; Data release
Country Canada
State British Columbia
Other Geospatial Vancouver Island
Online Only (Y/N) Y
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details