Hybrid Surface Wave Survey - A Combined Active and Passive Seismic Survey Using a Linear Array
T. Inazaki, H. Kisanuki, T. Kita and K. Hayashi
Event name: 24th European Meeting of Environmental and Engineering Geophysics
Session: Geophysics in Engineering Geology and Geotechnical B
Publication date: 09 September 2018
Info: Extended abstract, PDF ( 2.62Mb )
Price: € 20
We developed a combined active and passive surface wave survey method and named it Hybrid surface wave survey method. The Hybrid survey method deploys a linear geophone array to measure active and passive seismic data sequentially. Surface hitting using a wooden hammer is adopted as the active seismic source. In addition, traffic noises are measured using the same linear geophone array. A number of geophones are placed along a line at 0.3 to 2 m intervals to record active and passive data. Two dispersion curves, one is for a higher frequency part calculated from active data, the other is for a lower frequency part calculated from passive data, are combined to form a single dispersion curve to a specific CMP in a survey line. The method enables us to reconstruct a dense 2D S-wave velocity profile along a line up to 50 m in depth. One of the advantages of hybrid surface wave survey is its robustness to the traffic noises or active utilization of them vice versa. We have applied the hybrid surface wave surveys to more than 30 survey lines since 2013. Our field tests demonstrated the capability of the hybrid surface wave survey method in urban areas.