Seismo Lab Brown Bag Seminar

The landfall of Hurricane Isaac along Louisiana's Gulf Coast in August 2012 was witnessed by the seismoacoustic Transportable Array (TA) stations on its track. We analyze the imprints of Isaac's landfall in the recorded seismic ground displacements and infrasound pressure. Turbulent atmospheric pressure fluctuations within the hurricane boundary layer dominate in the period band ~20-100 s. We present a data-constrained interdisciplinary modeling workflow that combines large-eddy simulation (LES) of turbulence, calibrated by atmospheric datasets, with quasi-static elastic deformation modeling. Both infrasound pressure and vertical displacement spectra are well matched. The LES-derived turbulent pressure field connects the spatial and temporal scales, which is crucial for using point-measured data to invert for subsurface elastic properties from the pressure-displacement transfer function. Our LES results also constrain turbulent mixing under hurricane landfall conditions. Years of continuous data at multi-instrument seismic stations have the potential for novel applications in atmospheric studies for turbulence analysis, internal gravity waves observation, and more.