AMR-Accelerating Moment Release

Prediction NO Earthquake: Regional Seismicity Along the Wasatch Fault, Utah-2006 SCEC Abstract

Jamie Robinson, David Bowman, Ron Harris

Many large earthquakes are preceded by an increase in regional seismicity known as "accelerating moment release" (AMR).  It has been suggested that the observation of ongoing AMR can be interpreted as a signal that a fault is near the end of its seismic cycle.  We Present a preliminary attempt to search for AMR along the Wasatch Fault, a 240- mile long normal fault in north-central Utah.  Scenario events are based on the segmentation model of the 202 National Seismic Hazard Maps, and include multi-segment events.  A backslip dislocation model is used to calculate an approximate geologically-constrained loading model that defines the regions of precursory AMR for each scenario.  Seismicity data from the ANSS Composite Catalog do not show any significant ongoing AMR for any scenario event along the Wasatch Fault, suggesting that a major (M>6.5) earthquake on the fault is not likely in the next 5-10 years.