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SECOND EUROPEAN CONFERENCE ON EARTHQUAKE ENGINEERING AND SEISMOLOGY ISTANBUL | Turkey | Aug. 25-29, 2014 Feasibility study of a nation-wide Early Warning System: the application of the EEW software PRESTo on the Italian Strong Motion Network (RAN) Matteo Picozzi, Aldo Zollo, Luca Elia, Claudio Martino, Piero Brondi, Simona Colombelli, Antonio Emolo, Gaetano Festa, and Sandro Marcucci

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Worldwide EEWS At the nation-wide scale, the Japanese system uses ~1,000 seismic instruments across Japan, 200 operated by JMA and 800 by NIED, and integrates methodologies developed by JMA and NIED

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272 272 Free Field Stations: Force Balance 3-C. Accelerometer 18 bit digitizer GSM modem PGA via SMS 272 272 Free Field Stations: Force Balance 3-C. Accelerometer 18 bit digitizer GSM modem PGA via SMS ~ 500 ~ 500 Digital Strong Motion Stations: Local Storage on PCMCIA disk GSM / GPRS Modem to send waveforms cut between triggering and de-triggering Trigger at 0.1% g acceleration or on STA/LTA threshold (newer stations) Message containing PGA within 5 min. ~ 500 ~ 500 Digital Strong Motion Stations: Local Storage on PCMCIA disk GSM / GPRS Modem to send waveforms cut between triggering and de-triggering Trigger at 0.1% g acceleration or on STA/LTA threshold (newer stations) Message containing PGA within 5 min. 192 192 Stations in Cabins Force Balance 3-C. Accelerometer 24 bit digitizer GPRS router. No wait for coda to send data. PGA via e-mail 192 192 Stations in Cabins Force Balance 3-C. Accelerometer 24 bit digitizer GPRS router. No wait for coda to send data. PGA via e-mail RAN RAN RAN + ISNet RAN + ISNet Seismicity Seismicity The Italian Strong Motion Network (RAN) 3

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Feasibility of EW in Italy based on RAN Working hypotheses: -RAN in its actual configuration is upgraded to operate in real-time mode -Telemetry and data processing delays (1+1 sec) are those measured at ISNET using PRESTo Working hypotheses: -RAN in its actual configuration is upgraded to operate in real-time mode -Telemetry and data processing delays (1+1 sec) are those measured at ISNET using PRESTo

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An integrated software platform for real data processing and seismic alert notification An integrated software platform for real data processing and seismic alert notification Automatic procedures for the probabilistic and evolutionary estimation of source parameters and prediction of ground motion shaking. Automatic procedures for the probabilistic and evolutionary estimation of source parameters and prediction of ground motion shaking. Automatic Picking RT Earthquake Location RT Magnitude Estimation PGx Prediction at Targets Satriano & Elia (2010). PRESTo, the earthquake early warning system for Southern Italy: Concepts, capabilities and future perspectives. Soil Dyn Earthquake Eng PLUS http://www.prestoews.org/

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from INGV (http://esse1- gis.mi.ingv.it/ s1_en.php)

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3 stations6 stations Time of first alert between 4 and 12 sec Time of first alert between 5 and 15 sec

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3 stations6 stations Blind Zone radius between 30 and 49 km Blind Zone Radius between 35 and 57 km To compute the BZ radius: P-arrival time, P-wave time window, average telemetry and computation times at ISNET.

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DM defined as the PGV+ corresponding to the Instr.Int. VII class from Faccioli & Cauzzi (2006) Municipalities EWZ (PGV aver.) Lead-time 15.9 s EWZ (PGV+1) Lead-time 33.6 s EWZ (PGV-1) Lead-time 5.8 s BZ

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RTLOC RTMAG 40 EQs, Mw4.5, 2002-2013 from ITACA 2.0 (http://itaca.mi.ingv.it; Luzi et al., 2008; Pacor et al., 2011) Using 3 stations M < 0.5 T 1st Alert Error on hypocenteral location

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16921 hypothetical seismic sources (0.05x0.05) spacing For each node, the P-wave arrival times at 3 stations, are extracted assuming a gaussian reading error of 1 second Average Performance at National scale over 10 runs

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Performance at the National scale using 3 stations Percentage of successes (M est M true 0.5) at a national scale, using the first 3 stations. At each node : 10 simulated sequences in 50 years with 5 M max Percentage of successes (M est M true 0.5) at a national scale, using the first 3 stations. At each node : 10 simulated sequences in 50 years with 5 M max

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This study does not include the EW operability, which asks for massive experimental testing and close involvement of end-users The analysis of historical earthquake recordings and synthetics suggests that the integration of the RAN and PRESTo in an EEWS can provide, especially for the higher seismic hazard areas, reliable alert messages within about 5-10 seconds Expected errors on location and magnitude estimation,although large, are acceptable for peak ground motion predictions. The RAN seems to have the potential for a Nation-wide EEWS, but: The Communication Network Needs to be Expanded and Improved A Blind Zone extent of 30km is not acceptable for M 6 eqks The station density must be increased and onsite method should be used This study does not include the EW operability, which asks for massive experimental testing and close involvement of end-users The analysis of historical earthquake recordings and synthetics suggests that the integration of the RAN and PRESTo in an EEWS can provide, especially for the higher seismic hazard areas, reliable alert messages within about 5-10 seconds Expected errors on location and magnitude estimation,although large, are acceptable for peak ground motion predictions. The RAN seems to have the potential for a Nation-wide EEWS, but: The Communication Network Needs to be Expanded and Improved A Blind Zone extent of 30km is not acceptable for M 6 eqks The station density must be increased and onsite method should be usedConclusionsConclusions Thanks for your attention

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For a given earthquake source and the closest RAN stations, the peak displacement (PD) is randomly extracted from the PD-M relationship. Example for the 50 years EQ. sequences at the node of the 1980 Irpinia event PD valuesInput vs EEW M values Average RTMag success, false, and missed rate (in %) for the four MZ in case three stations are used. Success: M est M true 0.5 False: M est >M true + 0.5 Missed: M est M true + 0.5 Missed: M est