Extraction of P and Scholte waves from ambient seafloor noise observed
by distributed acoustic sensing
Abstract
Seismic wave extractions have been performed using ambient noise records
observed by distributed acoustic sensing (DAS) technology. Extractions
of microseisms can be investigated at a local scale using such DAS
records observed in the ocean. Here, we show P and Scholte wave
extractions from ambient seafloor noise observed by DAS along a
submarine cable deployed off Cape Muroto in the Nankai subduction zone,
Japan. The P waves can be observed at a frequency band of
0.1–0.3 Hz and up to a distance of 6–7 km. The distance in which the
P waves can be observed is controlled by the P incident
angle and the DAS sensitivity to the observable apparent velocity. The
effective extractions of P and Scholte waves are performed in
correspondence to large significant wave heights of the sea surface,
which indicate that these waves are originated from fluid distturbances
at the sea surface.