GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 2.1 GNGTS 2024 Discussion on long term PSHA – a workshop Daniela Di Bucci, Dario Albarello, Bruno Pace Within the 2024 GNGTS Conference, Session “Towards new approaches to estimate earthquake and tsunami hazard: a discussion”, a workshop has been organised, which aims at addressing issues related to the scientific and technical/applicative assessment of the various seismic hazard models that co-exist in various countries around the world, including Italy. They sometimes lead to the development of seismic hazard analyses whose results may differ in a way that is perceived as relevant. The workshop takes up and develops a previous event held Anacapri in September 2023 ( https://www.reluis.it/it/divulgazione/eventi/266-workshop-approcci-per-la-valutazione- dei-modelli-di-pericolosita-sismica-in-italia.html ) and includes contributes from eight invited speakers, followed by a general discussion. The focus is on long-term hazard in the Italian framework, at the national scale, in the Cornell-McGuire context, with a perspective on open problems that have not yet found a solution. This general theme has various possible areas of application in the background. Italy represents a unicum with respect to the availability of input data, seismological, geological and historical data; are they all used, and at their best, in seismic hazard models? Is there scope for improving models by considering unused or underused input data? The topic of uncertainties is developed in its different aspects: where do they lie with respect to the input data, where with respect to the modelling, how can they be correctly taken into account? And, finally, what consequences the differences between the hazard models considered (different models, updating of existing models, etc.) have in the various fields of application is addressed. In other words, what do we intend to do in this workshop? ● Discuss the topic of assessing seismic hazard models, in relation to both their scientific value and their practical use. ● Discuss the evolution of seismic hazard models over the last decades (including the role/development of uncertainties) and the consequences of this evolution on their use and on risk models. ● Identify proposals, possible solutions or aspects still to be explored And what we do NOT intend to do in this workshop? ● Discuss specifically one or the other of the models produced, except for the purpose of exemplification within the more general topics ● Discuss the role of scientific commissions that play roles in seismic hazard studies ● Go into the decision-making processes of the actors using seismic hazard models