Earthquake in northwest Arizona - magnitude 3.4

There was a magnitude 3.4 earthquake in northwest Arizona at 2:23 a.m. local time this morning.   The preliminary USGS location puts it about 30-40 km east of the ongoing earthquake swarm west of the Grand Wash Cliffs.  We are examining the records to see if adding data from the Arizona seismic network will change the location.   [Right, orange star marks epicenter.  Red lines are active faults, which are part of the Intermountain Seismic Belt. Credit, USGS]