Evaluation of 10 Years of UCERF3-ETAS Next-day Forecasts
Description:
Rigorous evaluation of earthquakes forecasts is a crucial step in understanding and improving the capabilities of earthquakes forecasting models. The UCERF3-ETAS model is currently the most advanced seismicity model combining a long-term seismicity model incorporating hypotheses of fault rupture dynamics and elastic rebounding with an Epidemic-Type Aftershock Sequence (ETAS) model for short-term seismicity. UCERF3-ETAS has also been used on demand for operational earthquake forecasting of important seismic sequences like the 2019 Ridgecrest one. Here, we have evaluated a very large database of UCERF3-ETAS next-day forecasts for California from 1 August 2008 to 31 August 2018. Each next-day forecast is composed of 100,000 synthetic catalogs generated by the model. The synthetic catalogs comprise events with magntiude Mw ≥ 2.5, start at 00:00:00 UTC, last 24 hours, and include all events prior to midnight in the history for generating the next day's forecasts. The 2008-2018 period comprises important seismic sequences, the most relevant being the 2010 7.2 Mw El-Mayor Cucapah sequence, as well as relatively quiet periods. Evaluating this extensive set of forecasts not only provides insights into the model's ability to accurately forecast daily seismicity, but also to understand which components drive the model in active and quiet periods, and the interplay between them. This is particularly evident when analysing the temporal evolution of quantities such as the magnitude or the spatial distribution provided by the forecast and how they change based on the history of the process. We assess the consistency between forecasts and observations using the statistical tests for catalog-based forecasts developed by the Collaboratory Study for Earthquake Predictability (CSEP), as well as Turing-style tests which provide an alternative way to evaluate a forecast visually.
Session: Improving the State of the Art of Earthquake Forecasting Through Models, Testing and Communication - I
Type: Oral
Date: 4/15/2025
Presentation Time: 02:30 PM (local time)
Presenting Author: Francesco
Student Presenter: No
Invited Presentation:
Poster Number:
Authors
Francesco Serafini Presenting Author Corresponding Author francesco.serafini@bristol.ac.uk University of Bristol |
Maximilian Werner max.werner@bristol.ac.uk University of Bristol |
Fabio Silva fsilva@usc.edu Statewide California Earthquake Center |
Philip Maechling maechlin@usc.edu Statewide California Earthquake Center |
Kevin Milner kmilner@usgs.gov Statewide California Earthquake Center, U.S. Geological Survey |
Edward Field field@usgs.gov U.S. Geological Survey |
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Evaluation of 10 Years of UCERF3-ETAS Next-day Forecasts
Session
Improving the State of the Art of Earthquake Forecasting Through Models, Testing and Communication