High frequency seismic noise generated from breaking swallow water ocean waves and the link to time-variable sea states

Abstract:

Breaking waves in the near-shore are known to generate a significant amount of high frequency ($f>5$ Hz) energy. We investigate the correlation between the spectrum of seismic energy and the local sea states. We deployed a single three-component broadband seismometer approximately $50$ m from the sea shore and recorded continuously for approximately 10 days. Our observations show that during elevated sea states, and presumably larger breaking waves in the surf zone, the power spectral density of the wave-generated seismic energy shifts to lower frequencies and higher spectral amplitudes. The correlation of the seismic spectral power to the height and period of ocean waves suggests that seismic observations can be used as a proxy for local sea states, which may have implications for sea shore sediment transport.