*Authors are listed in alphabetical order.
A note on the interpretation of seismic surface waves overthree-dimensional structures
Article first published online: 9 OCT 2008
Geophysical Journal International
Volume 143, Issue 2, pages 335–339, November 2000
How to Cite
Friederich, W., Hunzinger, S. and Wielandt, E. (2000), A note on the interpretation of seismic surface waves overthree-dimensional structures. Geophysical Journal International, 143: 335–339. doi: 10.1046/j.1365-246X.2000.01241.x
- Issue published online: 9 OCT 2008
- Article first published online: 9 OCT 2008
- Accepted 2000 May 30. Received 2000 March 27; in original form 2000 February 17
- Cited By
- phase velocity;
- structural interpretation;
- surface waves
In the 2-D acoustic case, the sound velocity of a heterogeneous medium can be determined from the amplitude and phase of almost any wavefield (but not from its phase alone) by inserting the wavefield into the Helmholtz equation and resolving for the wavenumber. Seismic surface waves in a laterally heterogeneous half-space do not obey the Helmholtz equation; however, when the heterogeneity is smooth, the Helmholtz equation is approximately valid for each mode separately. Using synthetic multimode wavefields, we investigate whether the same equation can be used to improve the structural interpretation of seismic surface waves. We find that the Helmholtz equation images lateral heterogeneity much better than the eikonal equation on which the conventional interpretation of surface wave dispersion is based.