Results of the Regional Earthquake Likelihood Models (RELM) test of earthquake forecasts in California

摘要

The Regional Earthquake Likelihood Models (RELM) test of earth quake forecasts in California was the first competitive evaluation of forecasts of future earthquake occurrence. Participants sub mitted expected probabilities of occurrence of M≥ 4.95 earth quakes in 0.1° × 0.1° cells for the period 1 January 1, 2006, to December 31, 2010. Probabilities were submitted for 7,682 cells in California and adjacent regions. During this period, 31 M ≥ 4.95 earthquakes occurred in the test region. These earthquakes occurred in 22 test cells. This seismic activity was dominated by earthquakes associated with the M = 7.2, April 4, 2010, El Mayor-Cucapah earthquake in northern Mexico. This earthquake occurred in the test region, and 16 of the other 30 earthquakes in the test region could be associated with it. Nine complete forecasts were submitted by six participants. In this paper, we present the fore casts in a way that allows the reader to evaluate which forecast is the most "successful" in terms of the locations of future earth quakes. We conclude that the RELM test was a success and suggest ways in which the results can be used to improve future forecasts.