Application of high-resolution seismic techniques in the evaluation of earthquake site response, Ottawa Valley, Canada |
| |
| Authors: | B Benjumea J A Hunter J M Aylsworth S E Pullan |
| |
| Institution: | Geological Survey of Canada, 601 Booth St., Ottawa, ON, Canada K1A 0E8 |
| |
| Abstract: | High-resolution seismic surveys, including P- and S-wave studies, have been conducted in an area of the Ottawa River valley located 80 km east of Ottawa (Canada). Based on dating of paleolandslides, the existence of paleoearthquake activity has been postulated in this area. The target zone for the seismic survey is characterized by surface disturbance and sediment deformation. P-wave seismic imaging was used to map the overburden–bedrock interface as well as to indicate reflecting boundaries within the overburden. The area of surface disturbance was found to overlie a buried bedrock basin, 8 km in diameter, infilled with a maximum thickness of 180 m of unconsolidated Quaternary sediments. Preliminary results of core logging show the presence of sand overlain by deformed fine sediments within the disturbed area. Shear-refraction studies reveal differences in the velocity–depth profiles between the disturbed area and the surrounding undisturbed areas. The shear-wave reflection method was used to produce a fundamental resonant period map for the area. Surface sediment disturbance was probably due to a combination of ground-motion amplification due to the basin (thick soft sediments) and the presence of water-saturated sand at depth. |
| |
| Keywords: | Seismic reflection Seismic refraction Earthquake site response Liquefaction Ground-motion amplification Eastern Canada |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
