A whole lot of shaking has been going on in Northern Arizona since March 28. It all started with a 2.3 earthquake near Littlefield in the northwestern corner of the state, but the most recent quakes are much stronger than scientists were predicting.
"The magnitude going above 3 is less common. Usually, smaller ones are more common, but with them going over 3 [on the Richter scale], we are going to start feeling them," Ramon Arrowsmith, a professor at Arizona State University's School of Earth and Space Exploration, said.
The earthquake swarm is situated near a small fault line of only about 10 miles.
"[It's] just west of Grand Canyon; people know it as Grand Wash Cliffs," Arrowsmith said.
Over the past year, moderate-size earthquakes have been reported across Arizona, including the one in Black Canyon City, a 4.1, and 4.0 on the night of Nov 2., which shook houses and buildings around the Valley.
"Arizona is on the boundary of the plate deformation zone between the North America and Pacific plate," Arrowsmith said.
On Wednesday, the leading earthquake scientist at the 2016 National Earthquake Conference in California warned that the San Andreas Fault is "locked loaded and ready to roll." The fault is moving at a rate of 35 millimeters a year.
"It's kind of like the rate your fingernails grow, and it's accumulating strain and will snap, and release at some time in a big earthquake," Arrowsmith explained.
Arizona will feel it in periods of long wave motions shaking the ground but not jolting it.
"Now part of the San Andreas Fault line does go through Yuma and so possible to have more damage in Yuma," Arrowsmith said.Copyright 2016 KPHO/KTVK (KPHO Broadcasting Corporation). All rights reserved.