HARMONIZING PROBABILISTIC SEISMIC HAZARD ASSESSMENT IN EUROPE: A MOMENT BALANCED APPROACH

Probabilistic seismic hazard assessment (PSHA) is one of the most useful products seismology offers to society. PSHA characterizes the best available knowledge on the seismic hazard of a study area, ideally taking into account all sources of uncertainty. Results form the baseline for informed decision-making, such as building codes or insurance rates and provide essential input to each risk assessment application.

Several large scale projects have recently been launched aiming to harmonize PSHA standards around the globe. SHARE (www.share-eu.org) is the EC-FP7 funded project to create community-based hazard model for the Euro-Mediterranean region. SHARE is a regional component of the Global Earthquake Model (GEM, www.globalquakemodel.org), a public/private partnership initiated and approved by the Global Science Forum of the OECD-GSF. In addition, large site-specific PSHA programs such as PEGASOS (CH) are ongoing and more are likely to be initiated as a consequence of the recent catastrophic M9 Tohoku event.

SHARE will deliver measurable progress in all steps leading to a harmonized assessment of seismic hazard - in the definition of engineering requirements, in the collection of input data, in procedures for hazard assessment, and in engineering applications. SHARE scientists create a framework and computational infrastructure for an integrated European PSHA model and specific risk scenario modeling tools. The results are envisioned to deliver long-lasting structural impact in areas of societal and economic relevance and will serve as reference for the Eurocode 8 (EC8) application, and will provide homogeneous input for the correct seismic safety assessment for critical industry, such as the energy infrastructures and the re-insurance sector.

Harmonizing hazard is pursued on the hazard input data level and the model building procedure across the entire extent of possible tectonic features across the European-Mediterranean territory. The effort requires transparent and reproducible strategies to estimate parameters such as the activity rates and maximum magnitudes. In this contribution we outline approaches of the SHARE model and how these are anchored to specific studies. The contribution will feature first preliminary results from the SHARE project.