Modeling of Longuet-Higgins Pressure Waves at the Seafloor for Energy Harvesting

Although ocean surface waves contain significant energy density, attempts to harness their energy have largely been limited to wave energy converter technologies deployed on or near the ocean’s surface. In this paper, we describe the modeling of a potentially harvestable energy, produced by ocean waves, and available at the sea floor (Korde UA and McBeth MS, unpublished white paper, 2019). It is in the form of a low-frequency underwater pressure variation, extending to the ocean bottom, which is due to interactions between opposing ocean waves. The theory of the physics for this effect was developed by Longuet-Higgins in 1950, and explains the generation of the so-called microseism and microbarom phenomena. The presence of such signals has been validated by seismic and infrasound monitoring stations worldwide. In this paper, we present the results of a first attempt to use a high-fidelity numerical model to study this pressure production mechanism, its dependencies, and it harvesting potential.