Near Surface P- and S-Wave Velocity Measurements VMF Vehicle Maintenance Facility, Seattle, WA Surface Refraction Data Interpretation: A north-south profile located in an industrial area on fill near the mouth of the Duwamish River. This site is in a region that was formerly an intertidal zone, which was subsequently massively infilled and converted to usable urban space about 100 years ago (Bortleson et al., 1980). Bortleson, G. C., Chrzastowski, M. J., and Helgerson A. K., 1980, Historical changes of shoreline and wetland at Duwamish River and Elliot Bay, Washington, U.S. Geological Survey Hydrologic Investigations Atlas HA-617 (sheet 7). P-vel (m/s) Depth (m) S-vel (m/s) Depth (m) 362 0.00 115 0.00 362 3.00 115 2.5 1500 3.0 131 2.5 1500 30.00 131 10.00 162 10.00 162 30.00 Seismic Recording Parameters Recording system Geometrics StrataView (30 channels activated) Sampling interval 0.001 seconds Record length 1 second Geophones Thirty 4.5-Hz horizontal; thirty 8-Hz vertical Geophone array linear with single phones at 3-m intervals Seismic Source 4.0 kg sledgehammer on metal plate (P-wave); 4.0-kg sledgehammer on wood timber (S-wave) Source array Reversed spreads with multiple off-end shots

P/S Velocity | Site Response | PACNW | Earthquake Hazards | USGS Modified Tuesday, October 30, 2001 by Susan Rhea This URL is: http://earthquake.usgs.gov/regional/pacnw/siteresp/svel/sitemap/vmf/index.html