Won Sang Lee, Minkyu Park, Yeadong Kim, and Byong-Kwon Park. Korea Polar Research Institute, Songdo Techno Park, Songdo-dong 7-50, Yeonsu-gu, Inchon, South Korea
Tertiary (T-) waves are seismically generated acoustic waves that propagate over great distances in the oceanic sound channel with little loss in signal strength even at relatively high (>1Hz) seismic frequencies. Although they were first identified almost fifty years ago, their excitation mechanism has not been clearly resolved. In this study, we address the effect of multiple anisotropic scattering on and below the seafloor in an attempt to explain quantitatively the generation of T-waves. We first apply a Monte Carlo simulation method based on the radiative transfer theory to deal with anisotropic multiple scattering on the seafloor and in the lithosphere. We then systematically compute the excitation of propagating acoustic modes using modal scattering. Lastly, we compare synthetic T-waves with those observed from data collected by seven Autonomous Underwater Hydrophones moored in the Bransfield Strait, Antarctica from November 2005 to November 2006.
