Large earthquakes often cause landslides, but in an unusual reversal, a massive landslide in a US copper mine in April 2013 might have resulted in a series of small earthquakes.

Credit: RAVELL CALL/DESERET NEWS/AP

Kristine Pankow and her colleagues at the University of Utah in Salt Lake City describe two sequential rock avalanches at the Bingham Canyon mine (pictured) near Salt Lake City. Together, these events comprise probably the largest non-volcanic landslide to have occurred in North America in modern times. The proximity of the landslide to a seismic monitoring network produced extensive data, which showed that the avalanches had an estimated magnitude of about 2.5. In the days following the landslide, the sensors detected 16 more seismic events.

GSA Today 24, 4–9 (2014)