Future earthquakes

While significant progress toward earthquake prediction has occurred in the past four years, the current guarded optimism for continued progress reflects in part revised goals and new definitions. First, recognition [e.g., Evernden , 1982] of the failures of the search during the 1970s for a reliable readily‐observable earthquake precursor has reemphasized the need to understand the fundamental physics of the earthquake generation process [e.g., Stuart , 1984/85] and brought acceptance of a probabilistic rather than a deterministic approach to earthquake prediction. That is, we now accept the notion that earthquake predictions must be couched in terms of probability gain and likelihood estimates. Second, a prediction terminology [ Wallace et al. , 1984] has been largely adopted that separates and expands the tasks into long‐term earthquake potential (no specific time window) and long‐term prediction (time windows of a few years to a few decades), where progress has been significant, and intermediate‐term prediction (time windows of a few weeks to a few years) and short‐term prediction (time windows up to a few weeks), where progress has lagged. In the 1970s, earthquake prediction usually was taken to mean a deterministic short‐term or intermediate‐term warning; now, probabilistic estimates of earthquake potential [e.g., Lindh , 1983; Sykes and Nirhenko , 1984] are accepted as the most reasonable and valid form for expressing the likelihood of a future earthquake and its hazards, as well as the uncertainties.