Oklahoma Quakes Rattle Nerves But Cause Little Damage

Nineteen earthquakes have shaken parts of the Oklahoma City area over the last seven days, causing little damage but fraying more than a few nerves.

The Oklahoman reports that the largest earthquake had a magnitude of 3.8, strong enough to do minor damage or knock unsecured items off shelves, said Rob Williams, a U.S. Geological Survey geophysicist in Golden, Colo.

Six of the 19 recent earthquakes have had a magnitude greater than 3. Transportation officials say crews were dispatched to inspect Oklahoma County highways, roads and bridges but no damage was found. Some of the earthquakes have been centered on or near the Kilpatrick Turnpike.

Williams told the newspaper that the quakes are likely connected to a central Oklahoma swarm of earthquakes that has been occurring since 2009. The swarm’s cause remains under study.

An earthquake with a magnitude of 2.5 to 3 is the smallest generally felt by people. A magnitude 4 can cause moderate damage, a magnitude 5, considerable damage, and a magnitude 6, severe damage. A magnitude 7 earthquake is capable of widespread and heavy damage.

Williams said the central Oklahoma earthquakes have occurred at relatively shallow depths and could have the potential for causing more damage than quakes that begin at greater depths.

“You can have damage from something smaller than a magnitude 4, especially if an earthquake is shallow and closer to homes, so the energy doesn’t get absorbed by the earth and dampened,” he said.

On Nov. 5, 2011, a 5.6-magnitude quake struck northwest of Prague, damaging more than a dozen homes and buildings and injuring at least two people. This earthquake broke the state’s previous record for strongest recorded earthquake, a 5.5-magnitude quake in 1952 in El Reno.

Could more quakes of this size or bigger occur?

“I can’t rule it out,” Williams said. “Oklahomans should continue to stay prepared for earthquakes, just like they prepare for tornadoes.”