Seismic structure of a seaward-dipping reflector sequence southwest of Rockall Plateau

Abstract

A seismic refraction line was obtained with a sonobuoy and airgun source over a seaward dipping reflector sequence on the southwest flank of the Rockall Plateau. The record section has been modelled using synthetic seismograms to obtain a well-constrained velocity/depth structure down to about 4 km below the top of the dipping reflector sequence. The smooth increase of velocity in the upper 1.5 km probably is due to the downward closure of cracks and voids. The base of the dipping reflector sequence beneath the profile is associated with the bottom of a relatively rapid increase in velocity from about 5.5–6.5 km s−1. A similar association of the base with a velocity increase from about 5.5–6.5 km s−1 off Queen Maud Land and under the Vøring Plateau suggests it may be a general feature of seaward dipping reflector sequences.