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The GEM Global Mosaic of Hazard Models: Improvements Since Its First Release and Challenges Ahead

Description: 

The GEM Global Mosaic of seismic hazard models (the mosaic herein) is a publicly accessible collection of models for probabilistic seismic hazard analysis that allows computation of hazard for inland areas globally. The mosaic includes 31 models developed by national institutions, international projects, groups of scientists and the GEM hazard team. They are all represented using the standard OpenQuake-Engine input model (a .xml markup language) and can be executed in this code to calculate different results. Since its first release at the end of 2018, the mosaic has undergone several improvements, mainly by replacing outdated hazard models with more recent versions or substituting obsolete components with more recent ones. For example, within a project executed in collaboration with the USGS, the GEM hazard team recently performed a comprehensive appraisal of the ground-motion models used and, where possible, replaced old models with more up-to-date versions. Extensive work was also put into homogenizing the minimum magnitude for calculation and obtaining more comparable hazard results across models.
There are various challenges the GEM hazard team is currently tackling to improve the mosaic. Some of the most important ones are to generate global forecasts for the whole set of models and improve the forecasting skills of individual models. The first goal requires the creation of hazard models covering the oceans, an activity we recently started, the homogenisation of models at their boundaries to avoid double counting and improvements within the OpenQuake Engine. The second objective needs improvements at the methodological level for both the model-building process and the calculation of hazard. For example, this entails the development of earthquake occurrence models with the ability to model the time-dependence and transients of seismicity, ground-motion models better calibrated on the local strong-motion information or more efficient ways to incorporate epistemic uncertainty and compute hazard results.

Session: Advances in Probabilistic Seismic Hazard Analysis and Applications

Type: Oral

Date: 4/19/2023

Presentation Time: 09:00 AM (local time)

Presenting Author: Marco Pagani

Student Presenter: No

Invited Presentation: No

Authors