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
First Break, 27 (7):
43--50 (July 2009)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.