Research Article| September 13, 2017 Performance of the GFZ Decentralized On‐Site Earthquake Early Warning Software (GFZ‐Sentry): Application to K‐NET and KiK‐Net Recordings, Japan Stefano Parolai; Stefano Parolai aCenter for Early Warning Systems Section, Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany, parolai@gfz-potsdam.de, tobias.boxberger@gfz-potsdam.de Search for other works by this author on: GSW Google Scholar Adrien Oth; Adrien Oth bEuropean Center for Geodynamics and Seismology, 19, rue Josy Welter, L‐7256 Walferdange, Grand Duchy of Luxemburg, adrien.oth@ecgs.lu Search for other works by this author on: GSW Google Scholar Tobias Boxberger Tobias Boxberger aCenter for Early Warning Systems Section, Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany, parolai@gfz-potsdam.de, tobias.boxberger@gfz-potsdam.de Search for other works by this author on: GSW Google Scholar Author and Article Information Stefano Parolai aCenter for Early Warning Systems Section, Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany, parolai@gfz-potsdam.de, tobias.boxberger@gfz-potsdam.de Adrien Oth bEuropean Center for Geodynamics and Seismology, 19, rue Josy Welter, L‐7256 Walferdange, Grand Duchy of Luxemburg, adrien.oth@ecgs.lu Tobias Boxberger aCenter for Early Warning Systems Section, Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany, parolai@gfz-potsdam.de, tobias.boxberger@gfz-potsdam.de Publisher: Seismological Society of America First Online: 13 Sep 2017 Online Issn: 1938-2057 Print Issn: 0895-0695 © Seismological Society of America Seismological Research Letters (2017) 88 (6): 1480–1490. https://doi.org/10.1785/0220170048 Article history First Online: 13 Sep 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Stefano Parolai, Adrien Oth, Tobias Boxberger; Performance of the GFZ Decentralized On‐Site Earthquake Early Warning Software (GFZ‐Sentry): Application to K‐NET and KiK‐Net Recordings, Japan. Seismological Research Letters 2017;; 88 (6): 1480–1490. doi: https://doi.org/10.1785/0220170048 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 SocietySeismological Research Letters Search Advanced Search ABSTRACT In this article, we report on the application of GFZ‐Sentry software for decentralized on‐site earthquake early warnings to a large data set of recordings collected by the Japanese K‐NET and KiK‐net seismic networks. The data set is composed of 3,225 three‐component recordings from 24 seismic events. The magnitudes of the selected earthquakes fall into a range of MJMA 6.0–7.3 (Mw 5.7–6.9) and cover hypocentral (epicentral) distances between 5 and 107 km (2 and 103 km, respectively). The data have been coordinated in real time with velocity and displacement; in this manner, the peak ground displacement (Pd) within the first few seconds (to a maximum of 3 s) after the P‐wave arrival in the vertical component is determined. This value is used to estimate the peak ground velocity (the median, along with the associated 16% and 84% confidence intervals) on the horizontal components using empirical relationships. Based on these values, the traffic light status (green, orange, red) is then determined following the methodology introduced by Parolai et al. (2015), which uses three matrices to show the relationship between the expected ground motion and the possible damage (in terms of seismic intensity) that may arise. The performance of the software was evaluated without making ad hoc calibrations for the area or the selected thresholds and was found to be quite reliable.For example, in 90% of cases, assignment of the “red” status is followed by shaking that leads to a seismic intensity equal to or greater than V (very light potential damage). Additionally, all of the recordings leading to an intensity greater than VII (moderate to heavy damage) were correctly classified by a red status. Similarly, when considering all the declared green statuses, it is remarkable that only in 10% of cases was there a “missed alarm” (i.e., a green status is determined, but due to the level of observed shaking, it is later seen that the status should have been red). You do not have access to this content, please speak to your institutional administrator if you feel you should have access.