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Earthquake Early Warning ShakeAlert System: Testing and Certification Platform

Cochran, Elizabeth S. and Kohler, Monica D. and Given, Douglas D. and Guiwits, Stephen and Andrews, Jennifer and Meier, Men-Andrin and Ahmad, Mohammad and Henson, Ivan and Hartog, Renate and Smith, Deborah (2018) Earthquake Early Warning ShakeAlert System: Testing and Certification Platform. Seismological Research Letters, 89 (1). pp. 108-117. ISSN 0895-0695. doi:10.1785/0220170138.

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Earthquake early warning systems provide warnings to end users of incoming moderate to strong ground shaking from earthquakes. An earthquake early warning system, ShakeAlert, is providing alerts to beta end users in the western United States, specifically California, Oregon, and Washington. An essential aspect of the earthquake early warning system is the development of a framework to test modifications to code to ensure functionality and assess performance. In 2016, a Testing and Certification Platform (TCP) was included in the development of the Production Prototype version of ShakeAlert. The purpose of the TCP is to evaluate the robustness of candidate code that is proposed for deployment on ShakeAlert Production Prototype servers. TCP consists of two main components: a real‐time in situ test that replicates the real‐time production system and an offline playback system to replay test suites. The real‐time tests of system performance assess code optimization and stability. The offline tests comprise a stress test of candidate code to assess if the code is production ready. The test suite includes over 120 events including local, regional, and teleseismic historic earthquakes, recentering and calibration events, and other anomalous and potentially problematic signals. Two assessments of alert performance are conducted. First, point‐source assessments are undertaken to compare magnitude, epicentral location, and origin time with the Advanced National Seismic System Comprehensive Catalog, as well as to evaluate alert latency. Second, we describe assessment of the quality of ground‐motion predictions at end‐user sites by comparing predicted shaking intensities to ShakeMaps for historic events and implement a threshold‐based approach that assesses how often end users initiate the appropriate action, based on their ground‐shaking threshold. TCP has been developed to be a convenient streamlined procedure for objectively testing algorithms, and it has been designed with flexibility to accommodate significant changes in development of new or modified system code. It is expected that the TCP will continue to evolve along with the ShakeAlert system, and the framework we describe here provides one example of how earthquake early warning systems can be evaluated.

Item Type:Article
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URLURL TypeDescription
Cochran, Elizabeth S.0000-0003-2485-4484
Andrews, Jennifer0000-0002-5679-5565
Meier, Men-Andrin0000-0002-2949-8602
Additional Information:© 2017 Seismological Society of America. Published Online 6 December 2017. Data and Resources: All test event data used by Testing and Certification Platform (TCP) are provided as miniSEED files and in tank file format at (last accessed November 2017). The Earthworm open‐source software is available at (last accessed November 2017). For Haywired website, see (last accessed November 2017). The unpublished manuscript by S. E. Minson, M.‐A. Meier, A. S. Baltay, T. C. Hanks, and E. S. Cochran, 2017, “The theoretical and observational limits of earthquake early warning: Timeliness of ground motion estimates”, submitted to Science Advances. The authors wish to acknowledge the entire ShakeAlert research and development team, many of whom provided valuable discussions that helped inform the design of the system. The authors also thank internal U.S. Geological Survey (USGS) reviewers Sarah Minson and Glenn Biasi as well as two anonymous journal reviewers and Associate Editor Brendan Crowell for their helpful and insightful comments.
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Record Number:CaltechAUTHORS:20171208-083947727
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Official Citation:Elizabeth S. Cochran, Monica D. Kohler, Douglas D. Given, Stephen Guiwits, Jennifer Andrews, Men‐Andrin Meier, Mohammad Ahmad, Ivan Henson, Renate Hartog, Deborah Smith; Earthquake Early Warning ShakeAlert System: Testing and Certification Platform. Seismological Research Letters ; 89 (1): 108–117. doi:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:83748
Deposited By: Tony Diaz
Deposited On:13 Dec 2017 04:58
Last Modified:15 Nov 2021 20:13

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