Designing a Network-Based Earthquake Early Warning Algorithm for California: ElarmS-2 (2013)

Research Article| December 24, 2013 Designing a Network‐Based Earthquake Early Warning Algorithm for California: ElarmS‐2 H. Serdar Kuyuk; H. Serdar Kuyuk Seismological Laboratory, University of California, McCone Hall, UC Berkeley, Berkeley, California 94720skuyuk@seismo.berkeley.edu Search for other works by this author on: GSW Google Scholar Richard M. Allen; Richard M. Allen Seismological Laboratory, University of California, McCone Hall, UC Berkeley, Berkeley, California 94720skuyuk@seismo.berkeley.edu Search for other works by this author on: GSW Google Scholar Holly Brown; Holly Brown Seismological Laboratory, University of California, McCone Hall, UC Berkeley, Berkeley, California 94720skuyuk@seismo.berkeley.edu Search for other works by this author on: GSW Google Scholar Margaret Hellweg; Margaret Hellweg Seismological Laboratory, University of California, McCone Hall, UC Berkeley, Berkeley, California 94720skuyuk@seismo.berkeley.edu Search for other works by this author on: GSW Google Scholar Ivan Henson; Ivan Henson Seismological Laboratory, University of California, McCone Hall, UC Berkeley, Berkeley, California 94720skuyuk@seismo.berkeley.edu Search for other works by this author on: GSW Google Scholar Douglas Neuhauser Douglas Neuhauser Seismological Laboratory, University of California, McCone Hall, UC Berkeley, Berkeley, California 94720skuyuk@seismo.berkeley.edu Search for other works by this author on: GSW Google Scholar Bulletin of the Seismological Society of America (2014) 104 (1): 162–173. https://doi.org/10.1785/0120130146 Article history first online: 14 Jul 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation H. Serdar Kuyuk, Richard M. Allen, Holly Brown, Margaret Hellweg, Ivan Henson, Douglas Neuhauser; Designing a Network‐Based Earthquake Early Warning Algorithm for California: ElarmS‐2. Bulletin of the Seismological Society of America 2013;; 104 (1): 162–173. doi: https://doi.org/10.1785/0120130146 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Abstract The California Integrated Seismic Network (CISN) is developing an earthquake early warning (EEW) demonstration system for the state of California. Within this CISN ShakeAlert project, three algorithms are being tested, one of which is the network‐based Earthquake Alarm Systems (ElarmS) EEW system. Over the last three years, the ElarmS algorithms have undergone a large‐scale reassessment and have been recoded to solve technological and methodological challenges. The improved algorithms in the new production‐grade version of the ElarmS version 2 (referred to as ElarmS‐2 or E2) code maximize the current seismic network’s configuration, hardware, and software performance capabilities, improving both the speed of the early warning processing and the accuracy of the warnings. E2 is designed as a modular code and consists of a new event monitor module with an improved associator that allows for more rapid association with fewer triggers, while also adding several new alert filter checks that help minimize false alarms. Here, we outline the methodology and summarize the performance of this new online real‐time system. The online performance from 2 October 2012 to 15 February 2013 shows, on average, ElarmS currently issues an alert 8.68±3.73 s after the first P‐wave detection for all events across California. This time is reduced by 2 s in regions with dense station instrumentation. Standard deviations of magnitude, origin time are 0.4 magnitude units, 1.2 s, and the median location errors is 3.8 km. E2 successfully detected 26 of 29 earthquakes (MANSS>3.5) across California, while issuing two false alarms. E2 is now delivering alerts to ShakeAlert, which in turn distributes warnings to test users. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.