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The QTM Seismicity Catalog: A template matching catalog for southern California

This page is the home for the Quake Template Matching (QTM) seismicity catalog for southern California. The official reference for this work is:


Ross, Z.E., Trugman, D.T., Hauksson, E., and P.M. Shearer (2019). Searching for Hidden Earthquakes in Southern California. Science.


Please see the paper and supplementary text for details on the construction of the catalog. The QTM catalog is a superset of the SCSN catalog for the period 2008-2017 and contains more than 1.81 million earthquakes. Here, we provide two separate catalogs:
  • 1) A catalog with 1.81 million earthquakes. This catalog has a minimum detection threshold of 9.5 times the median absolute deviation and includes everything. qtm_final_9.5dev.hypo
  • 2) A catalog with ~900,000 earthquakes. This catalog contains the highest confidence events and corresponds to a detection threshold of 12.0 times the median absolute deviation. qtm_final_12dev.hypo
We also provide the individual thresholds for users to subset the base QTM catalog as they please. It is emphasized that these catalogs are fully automated products and only a subset of the events have been manually reviewed.


If you use this catalog in your work, we ask that you cite the Science paper. Please also acknowledge the DOIs for SCSN and SCEDC as described below.


For additional questions, please contact Zachary Ross or Daniel Trugman.





The authors thank R. Crovella of NVIDIA for helping to optimize the CUDA code. The project was greatly facilitated by use of the Caltech HPC facility; Funding: This research was supported by USGS/NEHRP grant G18AP00028; NSF awards: EAR-1550704 & EAR-1818582; by the Southern California Earthquake Center, which is funded by NSF Cooperative Agreement EAR-1033462 and USGS Cooperative Agreement G12AC20038; and by the Los Alamos National Laboratory LDRD program.;


Data and materials availability: The QTM catalog will be publicly available from the Southern California Earthquake Data Center ( All waveform 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. All remaining data are available in the main text or the supplementary materials.