Arizona isn't known as a state with a whole lotta shakin' goin' on - but a large-magnitude earthquake could strike here at any time, state officials warn.
They're holding a "Great Arizona Shakeout" drill on Thursday to teach people what to do if a big quake hits.
A safety guide called "Arizona is Earthquake Country" has been posted online to further spread the word.
"Large earthquakes are rare in Arizona - but they do occur," said Michael Conway, a spokesman for the Arizona Geological Survey. "The two-minute Shakeout drill - drop, cover and hold on - provides a simple mechanism for surviving moderate to large earthquakes with minimum injuries."
The drill calls for dropping to the ground, taking cover under a sturdy table or desk and holding on to the cover object until the shaking stops, Conway said.
The Geological Survey and the Arizona Division of Emergency Management are asking state and local authorities as well as school districts to take part in the Shakeout event.
It's scheduled for 10:18 a.m. Thursday.
More than 9 million people in Western states took part in Shakeout events last year, Conway said. Organizers seek to have at least 50,000 people participate in Arizona this year.
ARIZONA AT RISK
Seismic monitors recorded 131 earthquakes in Arizona in 2011.
Most of those were small - with the largest being a 3.7-magnitude quake in Central Arizona. But experts say faults in Arizona, surrounding states and Mexico are capable of damaging earthquakes up to a magnitude of 7.5.
One example: the Sonoran Earthquake of 1887. That 7.4-magnitude temblor, with an epicenter about 40 miles southeast of Douglas, rocked an area of some 775,000 square miles, Conway said.
"Reports in Tucson included structural damage and people knocked off their feet by the shaking," he said. "Rockfall in the Catalina Mountains was so severe that people thought wildfires were raging when it was just dust rising from the many rockfalls. Fifty-seven people were killed in small towns south of Douglas. A similar event today would have drastic consequences for Southern Arizona."
Among other sizable earthquakes were three near Flagstaff in the years from 1906 to 1912. They ranged from 6.0 to 6.2 in magnitude.
Still, those of us who live in Tucson probably needn't lie awake at night worrying about major earthquakes.
A passage in the "Arizona is Earthquake Country" guide assesses the risk this way: "Applying the U.S. Geological Survey probability mapping tool to downtown Tucson, Arizona, the probability of a magnitude 6.0 earthquake occurring within 25 years and 31 miles is about 1 percent."
Go online to www.shakeout.org/arizona/ for information on taking part in the Great Arizona Shakeout drill.
quake guide online
A 44-page guide, "Arizona is Earthquake Country," includes detailed earthquake safety tips. Get it free online by going to repository.azgs.az.gov/uri_gin/azgs/dlio/1459 and clicking on the "Arizona is Earthquake Country" file.
Contact reporter Doug Kreutz at email@example.com or at 573-4192. On Twitter: @DouglasKreutz