4.7 quake rattles Arizona residents

PHOENIX (AP) - A moderate earthquake jostled residents of northern Arizona - a region where quakes are frequent but usually don't produce much damage or alarm.

The U.S. Geological Survey said the magnitude-4.7 temblor that hit Sunday night was centered 7 miles north of Sedona and 6 miles underground. There were no immediate reports of injury or major damage, though workers had to clear some rocks and debris from a highway between Sedona and Flagstaff.

"Business as usual," said David Brumbaugh, director of the Arizona Earthquake Information Center at Northern Arizona University. "It's nothing unusual to have earthquakes in this part of the state. Most of them are too small to be felt."

Still, more than 1,200 people used the U.S. Geological Survey's website to report that they'd felt the quake.

"I think what I heard was the house kind of rattling," said Donna Kearney Lomeo, a Sedona real estate agent. "It sounded like a bunch of balls rolling around on the roof."

Deana Irvine, a Flagstaff-area midwife, said the temblor had her thinking a plane might have crashed in her usually quiet neighborhood.

"I was surprised that it made noise," Irvine said. "It was really loud. It was rumbling and I was thinking it sounded like an explosion or a sonic boom."

Here are things to know about earthquakes in Arizona.

WHERE THEY'RE FELT

Earthquakes shake all corners of the state, but they're far more prevalent in northern Arizona and relatively infrequent in the desert cities where the vast majority of Arizonans live.

"You ask a lot of people around the state whether we have earthquakes and they can't believe we do - and we certainly do," said Jeri Young, a research geologist in Phoenix for the Arizona Geological Survey, a state agency.

While the U.S. Geological Survey lists a 5.6-magnitude quake on the Arizona-Utah border in 1959 as Arizona's strongest, Brumbaugh and Young said the largest quakes on record were three in northern Arizona that ranged in the 6.0-6.2-magnitude and occurred between 1906 and 1912.

TOLL FROM ARIZONA EARTHQUAKES

Unlike California, Arizona has had no earthquake in recorded history that caused deaths or injuries, according to the U.S. Geological Survey.

However, the 1906-1912 quakes caused boulders to roll down from nearby mountains onto a Coconino National Forest construction crew's camp, ripped a 50-mile crack in the earth north of the San Francisco Peaks and damaged houses in Williams.

Recent data recorded 10-15 mostly small earthquakes monthly in Arizona, but northwestern Arizona has faults capable of generating a 7.0 quake, Young said.

That was the magnitude of the 2010 quake that killed more than 300,000 people in Haiti.

EARTHQUAKE GEOLOGY

Northern Arizona is at the southern end of a seismic belt that extends northward into Canada, Brumbaugh said.

Young said scientists will analyze sensor data from the Sunday night quake "to find out where the stresses are."

Unknown for now is whether it is a precursor to a larger one yet to come, Young said. "As time goes on the probability that was the main event becomes greater."