On the application of the fk-MUSIC method to measurement of multimode surface wave phase velocity dispersion from receiver arrays

Abstract

The fk-MUSIC method, little known in earthquake seismology, is reviewed and compared with two other methods—frequency domain slant-stack and UC-diagram—for measurement of surface wave phase velocity dispersion from array seismic data. The three methods have been implemented in Python for this study and we assess their capabilities and sensitivity to data characteristics using a variety of synthetic tests. This is followed by application of the methods to data from the Transportable Array component of USArray. In terms of real data applications for regional studies, we conclude all three methods are effective only when data from very long station arrays (∼ 3 − 4 times the longest wavelength of interest, so > 2000 km for upper mantle studies) is available. Moreover, although fk-MUSIC provides high resolution, it is substantially less effective than the well established UC-diagram technique, at recovering multimode dispersion.