SCEC Award Number 18219 View PDF
Proposal Category Individual Proposal (Integration and Theory)
Proposal Title Earthquake Forecast Testing
Investigator(s)
Name Organization
David Jackson University of California, Los Angeles Yan Kagan University of California, Los Angeles
Other Participants
SCEC Priorities 5c, 2e, 5d SCEC Groups CSEP, EFP, CISM
Report Due Date 04/30/2020 Date Report Submitted 11/05/2020
Project Abstract
 Objectives are to work within CSEP to (1) develop tests of various features of our GEAR1 global forecast, (2) study how paleo-seismic and physics-based modeling can best improve seismic hazard estimates, (3) carry out retrospective and early prospective tests of forecast models published by the Working Group on California Earthquake Probabilities (WGCEP). The first two are continuing projects, while the third is largely new. In all of these efforts, we will develop simplified programs to implement CSEP tests, compare with official CSEP results, devise null hypotheses, and construct simple examples of forecasts and tests to make CSEP procedures more transparent.
Intellectual Merit We’ve tested how well earthquake occurrence agrees with prior forecasts and the assumptions behind them. This contributes to understanding earthquake processes, a major goal of the Earthquake Forecasting and Prediction project in SCEC. We also developed methods for associating finite ruptures on faults with prescribed descriptions of such events, a necessary step in evaluation forecasts of such events, and we tested some of these ideas on forecasts of the Working Group on California Earthquake Probabilities (WGCEP). Association and testing of finite ruptures have been major goals of the Collaboratory for Study of Earthquake Predictability (CSEP).
Broader Impacts Our research affects seismic hazard estimation, which has implications for public safety, risk management, and public policy. We’ve presented our results to students and faculty at universities, including UCLA, UCR, ETH Zurich, and at the 2018 and 2019 SCEC Annual meetings, showing how Physics, Geology, Geodesy, and Statistics can be combined to solve real world problems. We’ve discussed our analysis with students and faculty in Statistics, showing them applications and encouraging their participation in seismological research.

Exemplary Figure Figure 1: Cumulative occurrence of seismic and macro-seismic events with reported magnitude 7.0 and above (blue) and Paleoseismic events assumed to have comparable magnitudes. The reported hiatus of paleo-events after 1920 is not seen in the seismic data.