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The Southern California W Phase Moment Tensor Catalog

This page is the home for the W phase moment tensor catalog for southern California. The catalog and the map present the result of applying the Wphase source inversion algorithm (Kanamori and Rivera 2008) to the regional data from the Southern California Seismic Network (see Data and Materials). It includes events with M ≥ 5 or larger since 2000. Events with post-screening azimuthal gap > 270 degrees have been excluded. The last few columns in the catalog provide various quality control parameters ("rms": normalized misfit, "nst" and "nch": number of stations and channels retained for the inversion, "gap": azimuthal gap, "dist": distance from the initial location to the optimal centroid (horizontal grid search). and "cond" condition number of the inverted matrix (linear inversion for the 5-parameters of the zero-trace moment tensor at the optimal location). For each location of the centroid location and timing a linear inversion is performed by least-square fitting of the early time domain displacement traces filtered approximately between 20 s and 400 s (the specific band pass depends on the preliminary magnitude estimation. It moves to longer periods as the preliminary magnitude increases.

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Map 1. Events and their beachball diagrams in the W phase catalog. Only events with azimuth gap < 270 and number of contributing channels ≥ 10 are displayed.

Longitude: Latitude:

References

Kanamori, H., and Rivera, L. (2008). Source inversion of W phase: speeding up seismic tsunami warning, Geophys. J. Int., 175, 222–238 doi:10.1111/j.1365-246X.2008.03887.x

Acknowledgements

Data and materials availability: All waveform, metadata, and parametric data are available from the Caltech/USGS Southern California Seismic Network doi:10.7914/SN/CI; stored at the Southern California Earthquake Data Center, doi:10.7909/C3WD3xH1.