Investigating the ocean generated acoustic/seismic wavefields in NE Atlantic

In this study, we look at the comparison of 3D simulations of acoustic and seismic waves propagation with OBS data recorded across the shelf offshore Ireland and out into the Rockall Trough. Real and synthetic observations are combined to characterize both acoustic and seismic wavefields in the marine environment and particularly study secondary microseisms propagation from deep to shallow water to the land. Whereas the recorded OBS data show a strong change in the energy of "noise events" in the primary microseism band from the shelf to the land, the secondary microseism band is associated with stronger signal in the deep water compared to the shelf area. Furthermore, the data also highlight seasonal variations in the seismic and acoustic wavefields likely related to changes in noise source locations. The 3D simulations of acoustic and seismic waves propagation in the Rockall Trough look promising to reconcile deep ocean, shelf and land seismic observations as well as the effect of the water column and sediments thickness on "seismic ambient noise" generation and propagation. For instance, the simulations reveal interesting results on the acoustic/seismic coupling and its implication on the secondary microseisms source origin. This project is part of the Irish Centre for Research in Applied Geoscience (ICRAG), funded under the SFI Research Centres Programme and is co-funded under the European Regional Development Fund.