Print Quake makes valley shake
Written by Greg Ruland   
Thursday, 24 March 2011 00:00


Dozens of Verde Valley residents were startled when a 3.7-magnitude earthquake rippled through the area shortly before 1 p.m. Friday, March 18, according to Arizona Earthquake Information Center seismologist Lisa Linville.

There were no reports of injuries or damage caused by the quake, which was centered about seven miles northwest of Clarkdale, Linville said.

“We received several field reports from Cottonwood and Jerome,” Linville said. “People felt their patios, offices and homes shake, but no one reported any cracks or other damage to structures.”

“Yeah, I felt it,” said Frank Woodard, a Cottonwood resident. “I could hear the cupboards rattling. I thought, whoa, what’s going on here? It seemed like the ground was shaking for about 10 seconds.”

The epicenter of the a 3.7-magnitude earthquake was due north of Clarkdale, according to the U.S. Geological Survey.

Earthquake damage is related to the size of an earthquake, distance from the earthquake, and the ability of buildings and other structures to survive seismic shaking, she said.

For example, the recent earthquake in Japan, a 9.0-magnitude event, released about 160,000 times more energy than the quake in Clarkdale, Linville said. “As you go up in order of magnitude, the energy release increases by 32 times. It’s not linear,” Linville said.

In January, an earthquake in the same area registered a 3.5 magnitude. The highest earthquake in Arizona last year, measuring 3.58 took place June 25 at Roosevelt Lake..

The source of the earthquake was most likely the Big Chino Fault, but Arizona experiences so few earthquakes of significant magnitude, the state’s fault lines are not understood well enough to identify the precise location or cause of mild quakes, Linville said.

The ground does not normally rupture during a mild earthquake of 3.5 magnitude or less, she said.

“Large earthquakes in Arizona are rare, but not unheard of,” according to the Arizona Geological Survey website. The Colorado Plateau of Northern Arizona is particularly prone to moderate-sized earthquakes.