Love-wave MASW Analysis Example

Love-wave data can be acquired using horizontal source and receives oriented transversely with respect to the line of receivers. For comparison, Rayleigh waves are typically recorded using vertical source and receivers.

A corresponding seismic-record for Love-wave analysis.

Dispersion-curve imaging using the phase-shift method produced images on which is was possible to trace fundamental mode energy only to maximum ~20 Hz, i.e. could not provide information for the shallower part of the section.

Dispersion-curve imaging using the High-resolution Linear Radon Transform (HRLRT) is preferred because of the extended range of the fundamental-mode high frequencies (all the way to ~55 Hz in comparison to the ~20 Hz max) and higher modes, even when it used only half of the receiver spread.

Inversion of many multi-mode Love-wave dispersion curves and display of the 2D Vs results with variable depth

Love waves allowed us to obtain higher frequencies of the fundamental mode to sample the shallow part of the section something that Rayleigh waves couldn't (Ivanov et al., 2017).

The HRLRT allowed us to:

  1. Track fundamental mode to higher frequencies (when the conventional approach failed) and obtain reliable Vs results for shallower parts of the subsurface.
  2. Use a shorter spread while still being able to pick the fundamental mode trend from the larger spread and thus increase the lateral resolution because of the lesser averaging within the spread.
  3. Interpret higher modes and apply multi-mode inversion for Vs using, which allowed to:
    1. increase the vertical resolution by using more layers in the inversion without running into instabilities, and
    2. increase the depth of investigation because higher mode can "see" deeper.

For all the details...

Read more about Ivanov et al. (2017) at https://library.seg.org/doi/10.1190/INT-2016-0044.1 or download it from our publications page SurfSeis Publications.

Ivanov, J., R.D. Miller, D. Feigenbaum, S.L.C. Morton, S.L. Peterie, and J.B. Dunbar, 2017, Revisiting levees in southern Texas using Love-wave multichannel analysis of surface waves with the high-resolution linear Radon transform: Interpretation, 5, T287-T298. [available online]