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The earthquakes that struck eastern Türkiye and Syria on 6 February 2023 force us to evaluate the models of seismic hazard and risk developed at the European scale for the region, specifically the 2020 European Seismic Hazard Model (ESHM20, Danciu et al.. 2021) and European Seismic Risk Model (ESRM20, Crowley et al.. 2021).We first verified that the ruptures associated to the two main earthquakes are present within the inventory of ruptures within the source model (the earthquake rupture forecasts or ERFs) for the East Anatolian Fault (first event) and Sürgü-Cardak Fault (second event. Ruptures close in magnitude and dimension to those observed were present in the ESHM20 ERFs.Preliminary ground motion observations were found to be consistent in their prediction of the expected shaking and its attenuation. Recorded near-fault ground motions also suggest strong pulse-like behaviour, indicating the need for such phenomena to be better captured in the GMMs.We have finally run scenario risk calculations using the ESRSM20 site, exposure and vulnerability models for the two main earthquakes. Expected fatalities were lower than those reported at the time of writing; however, many factors contribute to this. Further analysis is on-going to understand the difference, but critical areas for future improvement to the risk models should include state-dependent fragility, modelling of further epistemic uncertainty in exposure and vulnerability, and inclusion of spatial- and temporal correlations in ground motions across a region.List of ESHM20 and ESRM20 core team members (all co-authors of this abstract) on www.efehr.com, The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

EFEHR Technical Report, 001

MARsite Project, funded under FP7-ENV.2012 6.4-2 (Grant 308417) and successfully implemented to Marmara Region during 2014-2016 indicated that focusing on the monitoring of the region and the integration of data from land, sea and space and the processing of this composed data based on sound earth-science research is an effective tool for mitigating damage from future earthquakes. This was achieved by monitoring the earthquake hazard through the ground-shaking and forecast maps, short- and long-term earthquake rate forecasting and time-dependent seismic hazard maps to make important risk-mitigation decisions regarding building design, insurance rates, land-use planning, and public-policy issues that need to balance safety and economic and social interests. MARSite has demonstrated the power of the use of different sensors in the assessment of the earthquake hazard. In addition to the more than 30 scientific publication within the MARsite Project framework, a multidisciplinary innovative borehole seismic observatory and a dilatometer have been installed within MARSite where its a data can be used for a range of seismic studies. Due to the encouraging results obtained from this experiment, it was determined that in the future likely smaller number of stations will be required reducing the cost of national seismic networks. The technical infrastructure of the continuous GPS stations of MAGNET network has been updated within MARSite. Tsunami hazard studies in MARSite in Marmara Sea showed that the tsunami hazard in the Marmara Region is primarily due to submarine landslides triggered by an earthquake and a conceptual Tsunami Early Warning System in the Marmara region strongly coupled with the strong ground motion and existing Earthquake Early Warning System was developed. The existing Earthquake Early Warning and Rapid Response system in the Marmara Region was improved and the installation and test of a pilot seismic landslide monitoring system was taken place in the Avcilar-Beylikdüzü Peninsula, a large landslide prone area located in westward part of Istanbul and facing the North Anatolian Fault Zone (NAFZ). An integrated approach based on multi-parameter seafloor observatories was implemented to continuously monitor the micro-seismicity along with the fluid expulsion activity within the submerged fault zone. During MARSite, strong integration and links had been established with major European initiatives focused on the collection of multidisciplinary data, their dissemination, interpretation and fusion to produce consistent theoretical and practical models, the implementation of good practices so as to provide the necessary information to end users, and the updating of seismic hazard and risk evaluations in the Marmara region. In this perspective, to continue the understanding of and improvement in the preparedness for geological disasters, the existing monitoring infrastructure of Marsite requires the continuation of a strong a European initiative. This presentation will provide a venue for information exchange towards the establishment of such an initiative.

Poster depicting the reference seismic hazard of the Middle East as obtained within the EMME Project

The MARsite Project, which started in November 2012,funded by the EC/ FP7-ENV.2012 6.4-2 (Grant 308417) identifies the Marmara region as a ‘Supersite’ within European initiatives to aggregate on-shore, off-shore and space-based observations, comprehensive geophysical monitoring, improved hazard and risk assessments encompassed in an integrated set of activities. MARsite aimed to harmonize geological, geophysical, geodetic and geochemical observations to provide a better view of the post-seismic deformation of the 1999 Izmit earthquake (in addition to the post-seismic signature of previous earthquakes), loading of submarine and inland active fault segments and transient pre-earthquake signals, related to stress loading with different tectonic properties in and around Marmara Sea. This presentation provides an overview of the achievements of MARSite which aimed to coordinate research groups ranging from seismology to gas geochemistry in a comprehensive monitoring activity developed in the Marmara Region based on collection of multidisciplinary data to be shared, interpreted and merged in consistent theoretical and practical models suitable for the implementation of good practices to move the necessary information to the end users in charge of seismic risk management of the region. In addition, processes involved in earthquake generation and the physics of short-term seismic transients, 4D deformations to understand earthquake cycle processes, fluid activity monitoring and seismicity under the sea floor using existing autonomous instrumentation, early warning and development of real-time shake and loss information, real- and quasi-real-time earthquake and tsunami hazard monitoring and earthquake-induced landslide hazard topics are also covered within MARSite. In particular, achievements and progress in the design and building of a multi-parameter borehole system consisting of very wide dynamic range and stable borehole (VBB) broad band seismic sensor, with incorporated 3-D strain meter, tilt meter, and temperature and local hydrostatic pressure measuring devices would be reported. Progress has been marked on photogeological analysis of DInSAR temporal series and of space multispectral/hyperspectral image data, an important geophysical field survey of one of the most important landslide that yielded a refined geological engineering model, numerical dynamic modelling of this and installation of a real-time monitoring system the field. We improved the existing earthquake early warning and strong motion networks and they are mostly integrated. The early warning signals extend to the critical infrastructure’s of Marmara Region like as natural gas distribution line IGDAS and transportation line MARMARAY). The project reached the following goals: intensive monitoring infrastructure have been installed, data sharing among the partners and researchers even the out of the Marsite project have been succesfully realized, more than 70 articles ,reports, presentations have been already issued (or published) and presented by 18 partners institutions.