SEGJ Technical Conference

High-resolution seismic reflection imaging of near-surface deformation structure of the Kureha-yama fault using Land Streamer

Abstract High-resolution shallow seismic reflection surveying by means of Land Streamer is capable to image detailed structure of a faulted zone down to 100 m. We adopted it for the delineation of near-surface deformation structure of the Kureha-yama fault, Toyama Prefecture. A 500 m-long seismic line was deployed to obtain P- and S-wave seismic profiles across the fault. CMP stacked sections profiled a low angle thrust faulting and related deformation structure at the frontal part in the near surface down to 200 m in depth. Other two 100 m-long parallel seismic lines were set along a railway where the fault was inferred to extend. S-wave CMP stacked sections delineated depression structure beneath flood deposits. The depression structure was concordant with interpreted structure of logs drilled near the lines. As a result, high-resolution shallow seismic reflection surveying using Land Streamer is helpful to provide valuable information regarding seismic zoning near an active fault for earthquake disaster prevention of infrastructures.