The article presents an analysis of the parameters of split shear waves from a surface (h = 8 km) earthquake that occurred within the Great Caucasus in Zagatala region on May 7, 2012 with ml = 5.6. Spatial analysis of waveforms is carried out using 3-component digital signal recordings. For selected sections of the 3-component recording in the DIMAS program, a three-dimensional graph of the particle motion path and the projection of the motion path on the NE, NZ, EZ planes is constructed. The birefringence effect, i.e. the shear wave is split into two (S1 and S2), each of which has its own polarization and speed for broadband three-component records (НHE, НHN, НHZ) of one seismic station ZKT. This made it possible to study small-scale strains for a better understanding of the dynamic processes and properties chances of the medium with depth. At the same time, the dependence of the parameters of split S waves on the direction of propagation and spatial heterogeneity of the physical properties of the medium requires a more detailed analysis of the data in space and time.It was established that the fast and slow S-waves are well distinguished in the wave field, their polarization vectors are mutually orthogonal. Subsequent waves have much smaller amplitudes, and their azimuths are close to the azimuth of the slow wave S2. The delay time between the first and second phases of the shear wave for the ZKT station is 3 seconds with the orientation of the polarization vectors along the azimuths 140º and 70º.

 

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https://en.wikipedia.org/wiki/Polarization_(waves)