By now Tucsonans have realized they were in fact not going crazy.
A 5.2 magnitude earthquake originating in Eastern Arizona did shake up their Saturday night and cause a momentary freak-out across Southern Arizona.
No injuries or major damage were reported.
Confirmation of the quake that rattled the region just before 10 p.m., near the Arizona-New Mexico border south of Duncan, came to the relief of those who took to social media to question their sanity and those watching horror films who wondered if they were experiencing paranormal activity.
Some made light of the event by posting stock photos of spilled drinks, a single toppled chair and an off-center painting with promises to rebuild after the few seconds of shaking were over. Others who were away on vacation were disappointed to miss the area’s most exciting seismic event in recent history.
And some didn’t feel a thing.
While Saturday’s quake is not common for the area, the event wasn’t triggered by supernatural forces, but was simply Mother Nature doing her thing.
“Our mechanism for this event was what we call normal faulting,” said Bruce Presgrave, a geophysicist with the U.S. Geological Survey’s National Earthquake Information Center in Golden, Colorado. “It’s kind of typical faulting of the basin and range province mostly associated with the state of Nevada, but Southern Arizona is considered to be part of the basin and range region.”
Quakes of similar magnitude have been felt in the area before, Presgrave said.
“Typically it’s what we call an extensional or spreading section within the North American plate. Most of the faults are nearly vertical faults that are extensional, that are spreading apart a little bit,” he said. “That’s why you get the basin and range region... as the earth gradually spreads in the plate, the valley floors slowly drop down and that’s what we call basin and range,” Presgrave said.
Saturday’s shock could be felt as far as Winslow and Albuquerque to the north, Alamogordo, New Mexico, to the east, in parts of the Mexican states of Sonora and Chihuahua to the south and Phoenix to the west.
As of Sunday afternoon, four aftershocks in the magnitude 3 range were recorded, mostly southeast of the epicenter, which is pretty typical, Presgrave said.
“I would expect that they would die out over the next day or so, but we never know. ... The earth always has surprises for us,” he said.
