A second opinion on "operational earthquake forecasting : some thoughts on why and how," by Thomas H. Jordan and Lucile M. Jones

In a recent Opinion in Seismological Research Letters, Jordan and Jones (2010) discussed the findings and recommendations of the International Commission on Earthquake Forecasting (ICEF) for operational earthquake forecasting convened by the Italian government following the 6 April 2009 L'Aquila Mw 6.3 earthquake, which killed 308 people in central Italy. "The goal of operational earthquake forecasting is to provide communities with information about seismic hazards that can be used to make decisions in advance of potentially destructive earthquakes" where "one of the outstanding challenges in the operational use of probabilistic forecasts is in translating them into decision-making in a low-probability environment" (Executive Summary, ICEF Report, Jordan et al. 2009). An underlying assumption of the ICEF report is that earthquakes cannot yet be deterministically predicted, so that only probabilistic earthquake (low-probability) forecasts are possible. This "Second Opinion" discusses a new understanding of fluid-rock deformation that provides the opportunity for deterministic earthquake stress-forecasting. This removes one of the "outstanding challenges." Deterministic forecasts can be made in a high-probability environment, which changes the emphasis of the ICEF report.