Exploration of the Body Wave Phases Generated by Ambient Noise Cross-correlation

Thursday, 18 December 2014
Shilin Li, ITAG Institute of Theoretical and Applied Geophysics, Peking University, Beijing, China, Ge Jin, LDEO, Columbia Univ., Palisades, NY, United States, Yongshun John Chen, Peking University, Beijing, China and James B Gaherty, Lamont -Doherty Earth Observatory, Palisades, NY, United States
Several recent studies have shown that it is possible to extract deep-penetrating body waves using seismic interferometry or ambient noise cross-correlation. Here we closely followed the method described by Bensen et al. in 2007 to obtain the vertical-vertical ambient noise cross-correlations using the earthquake’s code wave data of events with magnitude larger than 6 between 2012 and 2014 in China and South America. We observed several body wave phases such as PKIKP, PcPPKP and SKKS in the stacking result. We also generated 30 uniformly distributed events’ synthetic data for an antipodal station pair by mineos and processed them with the ambient noise cross-correlation. The match to the real data is very good and therefore, we believe that this can be explained by a 1-D earth model without scattering from lateral heterogeneities as in the standard ambient noise tomography. We also change the focal mechanism solution to find whether this can influence the phases’ relative amplitude.