New Observations of North-American Intraplate Dynamic Seismic Triggering and Prevailing Conditions

We systematically searched USArray seismograms for intraplate tremor and earthquakes that were dynamically triggered by the 2012 M8.6 Sumatra earthquake. We confirm triggered seismic activity along the western boundary of the North America and note the absence of triggered seismicity east of the Rocky Mountains. We newly observed dynamically triggered tremor near the Yellowstone hotspot, Wyoming, and triggered earthquakes in the Raton Basin and in central Utah. We then identified additional triggered events for each of these three locations by investigating seismograms recorded between 2001 to 2017. To advance our understanding and identification of the conditions that lead to dynamic triggering of seismic events, we applied a machine-learning algorithm (decision tree) to these three data sets as well as a published data set of known instances of triggered seismic tremor in central California. The algorithm found that dynamic stress estimates from teleseismic surface waves indeed appear to be a deciding f...