Microtremor spectra: a proven means for estimating resonant frequencies and S-wave velocities of shallow soils/sediments, but a questionable tool for locating hydrocarbon reservoirs

Over the past five years, established techniques for estimating the resonant frequencies and S‑wave velocities of shallow soil/sediment layers using microtremor spectra in the 1–10 Hz frequency range have been implicitly challenged by members of an industry-university consortium who claim that these same spectra can be used to map the detailed locations, depths, and thicknesses of hydrocarbon-rich sediments. But recently published spectral attributes based on 1–10 Hz microtremor recordings and associated analyses suggest that any microtremor signals originating from relatively deep hydrocarbon reservoirs are likely to be overwhelmed by surface-waves and other seismic energy travelling through the near-surface soil/sediment layers.