Blurring the boundary between earthquake forecasting and seismic hazard

Matthew C. Gerstenberger, David A. Rhoades, Graeme H. McVerry, David S. Harte, & Annemarie Christophersen

Submitted September 20, 2016, SCEC Contribution #6420, 2016 SCEC Annual Meeting Talk on 9/13 14:30 (PDF)

Earthquake forecasting and seismic hazard have been traditionally considered as independent and separate fields of study. We are currently working on a range of topics that are beginning to blur the bounds between the two fields. With the Canterbury earthquakes it became apparent that traditional methods of seismic hazard modelling would not fully represent the expected hazard in the coming 50 years and we developed a hybrid long-term and time-dependent hazard model that melded the two fields. A distinction of this model is that it combined a range of models that produced forecasts from one-year to 50-years. A major contribution to the estimated uncertainty in the hazard came from the expected occurrence rate for the region in 20 to 50 years time. We are now developing models to allow improved estimates of this rate and to better capture the epistemic uncertainty in the short to long-term processes. By using the hybrid model idea, we combine, in an alternative to logic-trees, models based on differing data sets or hypotheses to produce a forecast of earthquake occurrence. By combining information from such things as seismicity, geodetic strain, geological data and slow slip events, we can provide forecasts that are typically more informative than any single model. Additionally, we are trying to better characterize the uncertainty inherent in all of the models; through an improved understanding of this uncertainty, we can develop better statistical tests of the models, and ideally provide more useful information to decision makers who are using the outputs of such models both in the form of short-term earthquake forecasts and long-term hazard forecasts. Finally, through our experiences in Christchurch and more recent earthquakes in New Zealand, we have gained valuable experience in how to communicate earthquake forecast information and, also, perhaps, a unique perspective on where future earthquake forecasting and hazard research might be the most beneficial to end-users of such information.

Key Words
forecasting, hazard, uncertainty, communication, Canterbury, New Zealand

Citation
Gerstenberger, M. C., Rhoades, D. A., McVerry, G. H., Harte, D. S., & Christophersen, A. (2016, 09). Blurring the boundary between earthquake forecasting and seismic hazard. Oral Presentation at 2016 SCEC Annual Meeting.


Related Projects & Working Groups
Earthquake Forecasting and Predictability (EFP)