1. Application of SASHA for the Icelandic case Vera D’Amico 1, Dario Albarello 2, Ragnar Sigbjörnsson 3, Rajesh Rupakhety 3 1 Istituto Nazionale di Geofisica e Vulcanologia, Milano, Italy 2 Dip. Scienze Fisiche, della Terra e dell’Ambiente, University of Siena, Italy 3 Earthquake Engineering Research Centre, University of Iceland, Selfoss, Iceland

2. SASHA code Step 1 Step 2

3. Input elements used for Iceland Earthquake catalogue listing magnitude and epicentral intensity The SHare European Earthquake Catalogue (SHEEC) released by the EU project SHARE Attenuation model to estimate seismic effects at the site (expressed in terms of probabilities of exceedence of different intensity values) from epicentral information (epicentral intensity and epicentral distance) The probabilistic attenuation model developed in Task B with the empirical parameters assessed for Iceland

4. Earthquake catalogue Earthquakes extracted from SHare European Earthquake Catalogue (SHEEC) released by the EU project SHARE

5. Earthquake catalogue To apply the attenuation model of Task B, epicentral intensity I 0 is required for each earthquake of the catalogue A preliminary rough empirical relation was derived from the same events used to calibrate the attenuation model (these are the only events for which an estimate of I 0 is available!)

6. Earthquake catalogue I 0 derived from Mw (time period: 1706-2008)

7. Attenuation model by courtesy of Varini et al., 2013

8. Attenuation model

9. Hazard computation Hazard has been computed over a regular grid (1680 nodes) covering whole Iceland for 4 exceedence probabilities for an exposure time of 50 years, equivalent to average return times (ART) of 50, 200, 475, 975 years For 4 selected localities, further ARTs have been examined and hazard deaggregation performed

10. ART=50 (p.e. 63% in 50yr) ART=200 (p.e. 22% in 50yr) ART=475 (p.e. 10% in 50yr) ART=975 (p.e. 5% in 50yr)

11. Hazard curves ART=475 (p.e. 10% in 50yr) Hazard curves Iref

12. Hazard deaggregation ART=475 (p.e. 10% in 50yr) Distance (km) Magnitude Iref=8

13. Distance (km) Magnitude Hazard deaggregation ART=475 (p.e. 10% in 50yr) Iref=8

14. ART=475 (p.e. 10% in 50yr) Hazard deaggregation Distance (km) Magnitude Iref=8

15. Distance (km) Magnitude ART=475 (p.e. 10% in 50yr) Hazard deaggregation Iref=7

16. Comparison with previous PSHA ART=475 (p.e. 10% in 50yr) RT=475 (p.e. 10% in 50yr) PGA Just for qualitative comparison, because of different shaking measure (Intensity vs. PGA), different PSH methodology (SASHA vs. standard Cornell’s approach), different input data (catalogue, attenuation relation,…)