Earthquakes on Arizona-N.M. border felt in Valley   AZCentral - June 29, 2014

Four earthquakes occurred overnight between around 10 p.m. Saturday and 7:30 a.m. Sunday along the Arizona-New Mexico border ranging from a 3.4- to 5.2-magnitude, according to the United States Geological Survey. The earthquakes all occurred within the same general location, about 30 miles northwest of Lordsburg, N.M. The largest earthquake, a 5.2-magnitude, occurred around 10 p.m. on Saturday, followed by a 3.5, 3.4 and 3.6-magnitude earthquake that finished Sunday morning, according to USGS. The earthquake occurred within the North American tectonic plate and was caused by a normal spreading of the plate, Presgrave said. He said it is not uncommon to see such instances in the region where the earthquakes occurred due to a gradual spreading of the rock. Arizona residents in Graham County, Safford, Tucson, Gilbert, Mesa, Chandler and other areas have reported feeling the tremor.

Big Earthquakes Double in 2014, But They're Not Linked   Live Science - June 28, 2014

If you think there have been more earthquakes than usual this year, you're right. A new study finds there were more than twice as many big earthquakes in the first quarter of 2014 as compared with the average since 1979.