Speaker: Qing Ji, Stanford University
Title: Turbulent seismoacoustic imprints during a hurricane landfall
Time: Wednesday, Oct 1 at 12:00pm PST
Location: EMS B210
Abstract: 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 dominate in the period band ~20-100 s. We present an interdisciplinary modeling workflow that combines large-eddy simulation (LES) of turbulence, with quasi-static elastic deformation modeling. Both infrasound pressure and vertical displacement spectra are well explained. This inspires the direct application of infrasound ‘noise’ for turbulence analysis. In contrast to the sparse temporal resolution or intermittence of atmospheric data, infrasound data can be exploited to obtain the evolution of wind and turbulent dissipation rate during the hurricane passage. Our work opens a pathway to including infrasound data even for general atmospheric boundary layer study.
