Exploring Long and Short-term Time Dependencies in Earthquake Risk Modeling
Description:
State-of-practice earthquake risk modeling involves several important simplifications, which neglect (1) interactions between adjacent faults; (2) the long-term elastic-rebound behavior of faults; (3) the short-term hazard increase associated with aftershocks; and (4) damage accumulation in assets due to the occurrence of multiple earthquakes in a short time window. Several recent earthquake events (e.g., 2010 Canterbury earthquakes, New Zealand; 2019 Ridgecrest earthquakes, USA; 2023 Turkey-Syria earthquakes) have emphasised the need for models to account for the aforementioned short- and long-term time-dependent characteristics of earthquake risk. This work specifically investigates the sensitivity of earthquake risk metrics to these time dependencies for a case study portfolio in Central Italy. The end-to-end approach for time-dependent earthquake risk modeling used in this study incorporates (a) recent advancements in long-term time-dependent fault modeling and aftershock forecast; (b) vulnerability models that account for damage accumulation due to multiple ground motions occurring in a short time; and (c) consideration of time-dependent catastrophe risk insurance features. The sensitivity analysis results provide valuable guidance on the importance and appropriate treatment of time dependencies in regional (i.e., portfolio) earthquake risk models. We find that the long-term fault modeling and whether or not aftershocks are accounted for are the most important features to constrain in a time-dependent seismic risk model. If a large proportion of the assets in the portfolio has a high deductible, then accounting for damage accumulation also becomes important.
Session: Advancing Time-dependent PSHA and Seismic Risk Assessment: Accounting for Short- to Medium-term Clustering - I
Type: Oral
Date: 4/15/2025
Presentation Time: 10:30 AM (local time)
Presenting Author: Gemma
Student Presenter: No
Invited Presentation: Yes
Poster Number:
Authors
Salvatore Iacoletti salvatore.iacoletti@axaxl.com AXA XL |
Gemma Cremen Presenting Author Corresponding Author g.cremen@ucl.ac.uk University College London |
Carmine Galasso c.galasso@ucl.ac.uk University College London |
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Exploring Long and Short-term Time Dependencies in Earthquake Risk Modeling
Category
Advancing Time-dependent PSHA and Seismic Risk Assessment: Accounting for Short- to Medium-term Clustering