Design, Implementation and Testing of a Network-Based Earthquake Early Warning System in Greece

M Bracale,L Elia,V Karakostas,A Zollo,S Colombelli

doi:10.3389/feart.2021.667160

Abstract

In this study we implemented and tested the Earthquake Early Warning system PRESTo (PRobabilistic and Evolutionary early warning System, Satriano et al., 2011) on the Greek Ionian islands of Lefkada, Zakynthos and Kefalonia. PRESTo is a free and open source platform for regional Earthquake Early Warning developed at the University of Naples Federico II, which is currently under experimentation in Southern Italy, in the area covered by the Irpinia Seismic Network. The three Ionian islands selected for this study are located on the North-Western part of the Hellenic trench. Here the seismicity rate and the seismic hazard, coupled with the vulnerability of existing critical infrastructures, make this region among the highest seismic risk areas in Europe, where the application of Earthquake Early Warning systems may become a useful strategy to mitigate the potential damage caused by earthquakes. Here we studied the feasibility of implementing an Earthquake Early Warning system on an existing seismic network, which was not specifically made for earthquake early warning purposes, and evaluated the performance of the system, using a data set of real-earthquake recordings. We first describe the technical details of the implementation of PRESTo in the area of interest, including the preliminary parameter configuration and the empirical scaling relationship calibration. Then we evaluated the performance of the system through the off-line analysis of a database of real earthquake records belonging to the most recent M &gt; 4.0 earthquakes occurred in the area. We evaluated the performance in terms of source parameter estimation (location, magnitude), accuracy of ground shaking prediction and lead-time analysis. Finally, we show the preliminary results of the real-time application of PRESTo, performed during the period 01–31 July 2019.

Highlights

Every year devastating earthquakes cause enormous damage in terms of lives and serious threats for human activities in the active seismic regions of the world
During the last 20 years the development of Earthquake Early Warning Systems (EEWS) has allowed to reduce the potential damage directly related to the strong shaking caused by earthquakes or indirectly produced by fires, explosions, tsunamis and other phenomena triggered by the seismic event
Due to the unavailability of a massive catalogue for the considered area, we evaluated the prediction error for both PGA and PGV, using the standard ground motion prediction equation (GMPE) calibrated by Akkar and Bommer (2007) for the European large earthquake dataset and already implemented in PRESTo

Summary

Introduction

Every year devastating earthquakes cause enormous damage in terms of lives and serious threats for human activities in the active seismic regions of the world. The second example is the Mw 7.1 Morelos earthquake occurred on September 19, 2017, for which the short epicentral distance to Mexico City allowed for a few seconds of warning prior to the arrival of the S waves. In both cases, the warning was used to start public measures for reducing human losses in the city, including prompt evacuation of schools and buildings. The warning was used to start public measures for reducing human losses in the city, including prompt evacuation of schools and buildings Another relevant example of successful application of EEW alerts is the case of the Mw 9.0 Tohoku-oki (Japan) earthquake. About 90% of these people were able to take advance actions to save their own lives and those of family members or to take other actions according to prior planning (Fujinawa and Noda, 2013)

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