Sunday, July 24, 2016

Small quake felt in Arizona, New Mexico; aftershock to 2014 Duncan earthquake?

A magntiude 3.0 earthquake struck on the Arizona-New Mexico border just before 7 am this morning, and residents in both states report feeling it.  The preliminary epicenter calculated by the USGS is about 3-4 miles south of Duncan Highway - US70 between Lordsburg and Safford.  [right, orange star marks epicenter.  Credit, USGS]

AZGS has a temporary seismic station in the area following the Duncan M-5.3 earthquake of 2014, so we should be able to provide a more accurate location once those data are analyzed. We are still seeing numerous aftershocks from that event. 

Today's quake is roughly 10 miles south-southeast of Duncan and near the eastern edge of the aftershock zone from the 2014 main quake.  [Below, location of the 2014 Duncan main shock and aftershocks through September 2014.  Credit, Jeri Young, AZSG]  

I speculate that today's event is yet another in the ongoing aftershocks of that M=5.3 quake.


  1. Hello, cool blog, congrats! sorry for not understanding the area so much, but what is the source of all these quakes? results of the san andreas fault?

  2. Lucas, the quakes appear to be occurring on relatively small faults that are part of the Basin & Range extension regime, and not related to the San Andreas system.