Body wave phases from higher order cross-correlation

Zack Spica, & Gregory C. Beroza

Submitted August 8, 2016, SCEC Contribution #6552, 2016 SCEC Annual Meeting Poster #186

Recent studies in ambient field seismology showed that body wave phases (direct and reflected) can be extracted from ambient-field cross-correlations. The latter offers the possibility to sample Earth’s deep reflector (i.e. the outer core) in remote regions of the globe where traditional imaging techniques lack of earthquake signals. However, body wave phases retrieval using seismic interferometry depends on synchronousness of the seismic stations.
We show that we can go one step further and retrieve body wave phase between asynchronous seismic network using spatially stacked higher order cross-correlations (the so called C3). We present results for California and Mexico and we show that both direct P and/or ScS phases are clearly retrieved in the C3. Extraction of deep phases by higher order cross-correlations can therefore further improve the sampling of the deep Earth because the technique can be applied anywhere broadband seismic stations were once installed. In that sense, California is a good target for this study because hundreds of asynchronous network were installed since decades and we can take advantage of all of them to improve the deep Earth model of the region.

Key Words
Interferometry, body waves, C3

Spica, Z., & Beroza, G. C. (2016, 08). Body wave phases from higher order cross-correlation. Poster Presentation at 2016 SCEC Annual Meeting.

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