Seismic interferometry is a technique to estimate the Green’s function between two receivers by the use of the cross-correlation method with the aim of retrieving information about the subsurface. This study is aimed at appling ambient noise cross-correlations to data that have emerged continuously from vertical components of the Mantaro-Tablachaca seismic network in the central area of Peru between January and June 2010.
Cross-correlation was calculated in a period range from 1 to 10 seconds from data for 21 station pairs using 7 stations in this area. Dispersive waves in the cross-correlations were identified as surface waves. The group velocity for Rayleigh waves were estimated from multiple filtering analysis of the cross-correlations. The observed group velocities of Rayleigh waves were compared with the theoretical ones calculated from 1D P-wave models of an existing model in this area.
The observed group velocity dispersion curves show special variations of Rayleigh wave velocity; in NE directions CPA-TBL and QCH-TBL have low velocities than in other directions. This result indicates the advantage of the seismic interferometry processing of long term microtremors data, to obtain superficial wave dispersion measurement in this area.