Auxiliary material for Paper 2013GL057110

Seismic Interferometry with Antipodal Station Pairs

Fan-Chi Lin and Victor C. Tsai

Seismological Laboratory, Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA. (linf@caltech.edu)

Introduction

This auxiliary material contains four figures.
1. Figure S1. (a) Same as Figure 2b but for pair PAB-SNZO. (b) Daily PcPPKP amplitude for PAB-SNZO vs. BBSR-NWAO. Each day, the PcPPKP amplitudes for the two station pairs are determined based on daily cross-correlations at 1736-sec lag time. Clear correlation is observed between the two observed PcPPKP amplitudes, where significant negative amplitudes (<-0.008) tend to happen on the same days for the two station pairs. Considering that the two nearly antipodal station pairs are far away, this suggests that the coda excited by a large earthquake is at least semi-diffusive and that coda interferometry is not very sensitive to the precise earthquake location. 

2. Figure S2. Same as Figure 3 but for Feb 20, 2008. A Mw 7.4 earthquake happened near Simeulue, Indonesia (at ~35 km depth) at 8:08am UTC time.

3. Figure S3. Same as Figure 3 but for pair PAB-SNZO. 

4. Figure S4. Earthquake coda auto-correlations for five GSN stations using all Mw>7.0 earthquakes between January 1st 2000 and December 31st 2009. Several observed body-wave phases are indicated.