Ambient seismic noise and surface wave tomography of the Thinia Valley (Kefalonia, Greece)

An extensive active and passive seismic survey was carried out in the Thinia Valley (Kefalonia Island, Greece) in May 2022 to investigate the complex geo-structural setting of the area. Surface waves retrieved from the active seismic surveys provided velocity models along the investigated lines. To potentially increase the investigation depth, a passive 2D array of seismic stations continuously acquired ambient seismic noise in the area between the active lines for three days. The passive recordings were preliminary treated for the retrieval of surface waves through a Frequency Domain Beam Forming Method. Few useful events were detected due to the short duration of the acquisition and the lack of strong anthropic noise sources in the area. To increase the coverage, ambient noise interferometry was carried out on the passive data, with successful results. Ambient noise tomography demonstrated to be a valid complementary tool for the retrieval of a subsurface velocity model, when the passive data lack information on the noise source azimuth.