| Title | Geoscientific studies of Champlain Sea sediments, Bilberry Creek, Ottawa, Ontario: firm ground depth estimation through microtremor horizontal-to-vertical spectral ratios (HVSR) |
| Download | Downloads |
| |
| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Dietiker, B |
| Source | Geological Survey of Canada, Open File 8729, 2020, 14 pages, https://doi.org/10.4095/326172  Open Access |
| Image |  |
| Year | 2020 |
| Publisher | Natural Resources Canada |
| Document | open file |
| Lang. | English |
| Media | on-line; digital |
| Related | NRCan photo(s) in this
publication |
| Related | This publication is related to Geoscientific studies of
Champlain Sea sediments, Bilberry Creek, Ottawa, Ontario: on-site preservation of cores |
| File format | readme
|
| File format | pdf; rtf; saf (ASCII) |
| Province | Ontario |
| NTS | 31G/05; 31G/06 |
| Area | Ottawa; Bilberry Creek; Voyageur Creek |
| Lat/Long WENS | -75.5500 -75.4833 45.4833 45.4500 |
| Subjects | surficial geology/geomorphology; geophysics; engineering geology; Nature and Environment; Science and Technology; marine sediments; seismic methods; seismology; seismic waves; s waves; seismic
velocities; spectral ratios; amplitude spectra; boreholes; field methods; in-field instrumentation; floods; slope stability analyses; Champlain Sea Sediments; Phanerozoic; Cenozoic; Quaternary |
| Illustrations | photographs; location maps; geoscientific sketch maps; plots; tables; seismic profiles; digital elevation models; spectra; time series |
| Program | Public
Safety Geoscience Intraplate Earthquakes |
| Released | 2020 07 09 |
| Abstract | (Summary)
To support selection of prospective sediment drilling sites in Orleans (Ottawa), geophysical investigations allowed a rapid estimation of depth to firm ground for several candidate
locations within Champlain Sea deposits. In the Bilberry and Voyageur Creek areas, 12 ambient seismic noise measurements were recorded. Processed data from all sites fulfilled criteria for a reliable Horizontal-To-Vertical Spectral Ratio (HVSR) curve
and a clear resonance peak at the fundamental resonant frequency for soft soil. Despite the low-frequency noise from windy weather and sub-optimal instrument-ground coupling, 11 sites had peak amplitudes between 6.3 and 9.8. One site had a broad peak
and a low amplitude of 3.5, suspected to correlate with a dipping firm ground surface. Fundamental resonance frequencies range from 0.81 to 1.31 Hz, which translate to firm ground depths of 80 to 43 m below surface. The deepest site is located near
Voyageur Creek. Within the Bilberry Creek watershed, the deepest sites are located within upstream reaches towards the southeast. |
| Summary | (Plain Language Summary, not published)
The Rideau Valley Conservation Authority (RVCA), the City of Ottawa and the Geological Survey of Canada (GSC) are investigating potential flood risk and
slope stability hazards in the Champlain Sea muds along Bilberry Creek in Orleans, Ottawa, Ontario. The goal of this study is to find the thickest sediment sequence for further drilling, coring and geotechnical investigations. At 12 of the suggested
17 sites geophysical investigations estimated mud thicknesses of 43 to 80 m. This report describes the measurement technique, interprets the results and publishes the collected raw data and the final results. |
| GEOSCAN ID | 326172 |
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