Comparison of three surface wave measurements and a seismic downhole measurement in a complex-layered system

摘要

Three commercially-available seismic surface wave methods (SWM) were tested at a challenging site containing a high velocity layer (HVL). Methods tested included two active-source SWMs, the Spectral Analysis of Surface Waves method and the Multichannel Analysis of Surface Waves method; and one passive-source SWM, the Refraction Microtremor method. A borehole log and data from a shallow downhole seismic measurement were also available for comparison. While shear wave velocity profiles for the three methods were different, slowness-averaged velocities were comparable. None of the SWMs successfully resolved the HVL. The underlying cause can be the inherent capacity of the methods for averaging velocity with depth.