Issues

Front: Since 1 October 2015, the global earthquake activity rate (GEAR1) seismicity model has undergone prospective evaluation within the Collaboratory for the Study of Earthquake Predictability (CSEP) testing center, forecasting M_w ≥ 5.95 seismicity. As part of this issue’s Focus Section on the Collaboratory for the Study of Earthquake Predictability (CSEP): New Results and Future Directions, Strader et al. present initial prospective forecast test results for the GEAR1 model, its tectonic and seismicity components, and the first iteration of the strain-rate-based model, during the 1 October 2015–7 September 2017 period. Forecast maps showing M_w ≥ 5.95 earthquake epicentroid rates for GEAR1 and other models are illustrated here.

Back: Linville et al. (Electronic Seismologist, this issue) present a frequency domain array-based detection algorithm that exploits the gridded station configuration of the EarthScope Transportable Array to detect and locate small magnitude (M < 2.5) earthquakes. The authors apply the method to three sedimentary basins in the central United States as well as a dataset from Yellowstone National Park. Results from the Yellowstone data demonstrate that when array station spacing remains regular, events from nonearthquake sources such as hydrothermal features can be successfully detected and located without the necessity to tune parameters for specific sources. Daytime (red, assumed anthropogenic) and nighttime (yellow) detections from one day of data from the Doublet Pool and Old Faithful are shown.