Coal Bursting at the Elk Creek Mine: A Western United States Case Study

Coal bursts pose a substantial threat to operations and mine workers. The coal mines in the North Fork Valley (NFV) in the United States (US) have experienced many coal bursts, often with distinct characteristics from those of other US coal mining regions. Seismic monitoring in conjunction with other in-mine instrumentation was conducted at the Elk Creek Mine in the NFV during the mining of four longwall panels. Nearly one million seismic events with magnitudes ranging between − 2.0 and 3.1 were detected, of which approximately 200,000 located within the study region surrounding the extracted panels with 80 m location errors. Five events were coal bursts that resulted in injury or significant in-mine damage. This study examines the characteristics of the recorded seismicity, focusing on the largest magnitude coal burst. The moment tensor solution for the largest event corroborates the findings of other studies that faulting contributed to the damaging seismicity at the mine. Anomalous ground conditions, abnormal caving behavior, and the migration of seismic events characterized a latent seismic hazard that later resulted in a large coal burst. Moreover, the observed load transfer distance at the mine is significantly greater than what is suggested using common empirical design methods, which are largely based on coal mines in the Eastern US. This case study provides an example of the utility of seismic data at a burst-prone underground coal mine. The Elk Creek dataset, which is co-published with this study, is a valuable resource for future mine safety research.