Earthquakes decline in Oklahoma in 2012

The number of small Oklahoma earthquakes was down in 2012. There has been a significant increase in earthquakes in recent years, however.
BY ROBERT MEDLEY rmedley@opubco.com Published: February 11, 2013

The number of earthquakes in Oklahoma declined in 2012 following a two-year spike, said Austin Holland, a seismologist at the Oklahoma Geological Survey in Norman.

Holland moved to Oklahoma to study the sudden swarm of earthquakes that started in late 2009.

Before the spike began, the state averaged about three reported earthquakes felt each year dating back to when records were first kept. An earthquake of magnitude 2.5 to 3.0 is the smallest generally felt by people.

Thirty-eight earthquakes were felt in 2009.

Then 104 earthquakes were reported in 2010 and 97 in 2011, Holland said. The number dropped to 64 in 2012.

The area of Oklahoma with the most earthquakes continues to be centered in Jones in eastern Oklahoma County.

About 35 miles east in Lincoln County, the big one hit Nov. 6, 2011.

The 5.7 magnitude quake — the largest recorded in state history — was centered near Prague along the Wilzetta fault line, Holland said.

That record earthquake reportedly was felt as far away as Illinois and Tennessee.

Widespread damage

Earthquakes aren't the deadliest natural disasters in Oklahoma, but they can cause the most damage suddenly over the largest area, said Joey Wakefield, Lincoln County's emergency management director.

Assessing the damage from the 5.7 magnitude quake took much longer than determining tornado damage, Wakefield, said.

There were 460 reports of damage to buildings — broken bricks, cracks in walls, roof damage, chimneys separated from houses — and two homes destroyed, he said.