2nd year SAFER Project meeting. Armada Hotel, Istanbul, Turkey June, Information-dependent lead time maps for earthquake early warning in the Campania region Iunio Iervolino Assistant Professor of Structural Engineering Dipartimento di Ingegneria Strutturale Università degli Studi di Napoli Federico II, Naples, Italy.

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps Naples Hospitals Fire Stations Lifelines Factories Railways Highways 4 Cities The Campanian case

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps Source-to-site distance Seismic network Ground motion at the site IM (i.e. PGA) Structural/non-structural performance/loss EDP (i.e. Maximum Interstory Drift Ratio) Epicenter Signal at the network stations Site-Specific Warning by Regional Networks

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps PDF of magnitude conditioned to the measures of the seismic instruments PDF of distance due to rapid localization method Ordinary Attenuation relationship Prediction of peak ground motion at the site Real-Time Hazard Analysis for Hybrid EEWS

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps Real-Time loss assessment Extending the hazard approach it is possible to determine the expected losses conditioned to the measurements of the seismic network in the case of alarming or not Expected Loss 1. Loss probability depending on the alarming decision 2. Structural damage probability depending on buildings seismic response 3. Seismic response probability depending on hazard 4. Real-time hazard analysis ExposureVunerabilityHazard

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps How to set the alarm threshold: a simple example Lets consider a simple school class equipped with a ringer and suppose that the students are trained to shelter under the desks when the alarm is issued. What Causes Loss: 1.Structural collapse (causes death) 2.Non-structural collapse (causes injury and eventually death) 3.False alarm (cause panic and down-time loss) Security action 1.Sheltering below desks may reduce losses in the case of non-structural collapse

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps M=6.6, Site at 131km far from the network Naples Estimation of Magnitude Estimation of Distance Estimation of PGA at the site

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps Uncertainty Analysis Uncertainty due to the attenuation law Coefficient of Variation of the Estimation

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps Uncertainty Analysis Findings Uncertainty on distance is confirmed to be negligible in EEW calculations; Also uncertainty on magnitude, altough larger than distance, is small if compared to that of the attenuation law; It is important to compute the hazard analysis including the uncertainty of the attenuation, which is the most important (this allows to copute missed and false alarm rates); To issue the alarm it is important to assess whether the level of information it is stable. E.g., triggering more station does not change the decision of alarming or not.

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps Decisional rule PGAc Pc ALARM ! Because the probability that PGA exceeds the limit value is too high

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps Lead-time maps, defined on a 2700 nodes grid covering the whole Campanian territory, have been computed as a function of the number of stations triggered. Events occurring in the area covered by the ISNet infrastructure have been consideredred (hypocentral depths in Campania are small ranging from ~ 4 to ~ 12 km).

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps D E S I G N M A P

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps Lead-time maps for the case-study region can be superimposed to real-time risk reduction actions for specific structural systems. These security measures can be classified according to the time required to be carried out.

Information-dependent lead time maps for earthquake early warning in the Camapania region Done so far: RT- PSHA & Threshold setUncertainty AnalysisTo doLead-Time Maps To the end of the project Design of a semi-active control system applied to a structure; The system may be tuned in real-time on the basis of a prediction of the response spectrum; Simulation of the system and risk assessment; If the EEWS lead to a reduction of the annual risk the EEWS is effective on the earhquake engineering perspective.