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

Abstract

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.