SEGJ Technical Conference

Imaging of the near- and off-fault deformation of the western marginal fault of the Echigo Plain by means of high-resolution Land Streamer seismic reflection surveying.

Abstract High-resolution shallow seismic reflection surveying using Land Streamer is capable to image the near- and off-fault deformation structure in a faulted zone. We adopted newly assembled P- and S-wave type Land Streamers for the delineation of paleoseismic deformation events caused by the western marginal fault of Echigo Plain, Niigata Prefecture. A 1.4 km-long seismic line, and two 1 km-long lines were deployed to obtain P- and S-wave seismic profiles respectively at Akatsuka, Nishi Ward, Niigata City. As a result, CMP stacked migrated sections clearly profiled the major on-fault flexure structure and off-fault primary faultings in the near surface down to 200 m in depth. Correlation of seismic profiles with the drilled core and logging data obtained at GS_NAK1 and GS_NAK2 sites enabled to distinguish the recent paleoseismic events and to assess their ages and recurrence intervals.