Retrospective evaluation of the five-year and ten-year CSEP-Italy earthquake forecasts

Warner Marzocchi Warner Marzocchi,Stefan Wiemer Stefan Wiemer,Csep-Italy Working Group CSEP-Italy Working Group,Maximilian J. Maximilian J.,J. Douglas J. Douglas

doi:10.4401/ag-4840

Warner Marzocchi Warner Marzocchi, Stefan Wiemer Stefan Wiemer + Show 3 more

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https://doi.org/10.4401/ag-4840

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Abstract

On August 1, 2009, the global Collaboratory for the Study of Earthquake Predictability (CSEP) launched a prospective and comparative earthquake predictability experiment in Italy. The goal of this CSEP-Italy experiment is to test earthquake occurrence hypotheses that have been formalized as probabilistic earthquake forecasts over temporal scales that range from days to years. In the first round of forecast submissions, members of the CSEP-Italy Working Group presented 18 five-year and ten-year earthquake forecasts to the European CSEP Testing Center at ETH Zurich. We have considered here the twelve time-independent earthquake forecasts among this set, and evaluated them with respect to past seismicity data from two Italian earthquake catalogs. We present the results of the tests that measure the consistencies of the forecasts according to past observations. As well as being an evaluation of the time-independent forecasts submitted, this exercise provides insight into a number of important issues in predictability experiments with regard to the specification of the forecasts, the performance of the tests, and the trade-off between robustness of results and experiment duration. We conclude with suggestions for the design of future earthquake predictability experiments.

Highlights

On August 1, 2009, a prospective and competitive earthquake predictability experiment began for the region of Italy [Schorlemmer et al 2010a]
The experiment followed the design proposed by the Regional Earthquake Likelihood Model (RELM) working group in California, USA [Field 2007, Schorlemmer et al 2007, Schorlemmer and Gerstenberger 2007, Schorlemmer et al 2010b], and it falls under the global umbrella of the Collaboratory for the Study of Earthquake Predictability (CSEP) [Jordan 2006, Zechar et al 2010b]
We present the results from the retrospective testing of these forecasts on seismicity data from two Italian earthquake catalogs

Summary

Introduction

On August 1, 2009, a prospective and competitive earthquake predictability experiment began for the region of Italy [Schorlemmer et al 2010a]. In the context of the CSEP-Italy experiment, a seismicity forecast is a set of estimates of the expected number of future earthquakes in each bin, where the bins are specified by intervals of location, time and magnitude within the multidimensional testing volume [see Schorlemmer et al 2007].

Results

Conclusion