Earthquakes Common East, West Of Northwest Arkansas

Posted: July 13, 2014 at 1:30 a.m.


Northwest Arkansas sits almost exactly between two of the most seismically active regions of the country, and seismologists say the risk of a significant earthquake is growing.

At A Glance (w/logo)

The Magnitude Scale

Earthquake size is measured on how much the ground moves. It’s based on multiples of ten, meaning increase, such as from 2 to 3 or from 6 to 7, corresponds to a 10-fold increase in ground motion. Energy released, meanwhile, climbs even faster in relation to the number value. This means destructive power increases exponentially up the scale.

• 2.5-3: Generally the smallest quakes noticeable by humans.

• 3.8: The largest earthquake in Arkansas in the past three months, recorded near Greers Ferry Lake on June 4 and six times bigger than a magnitude 3.

• 5.6: Oklahoma’s largest quake, measured in 2011 and 63 times bigger than a magnitude 3.8.

• 7.7: USGS estimate of the largest quake on the New Madrid fault in 1811, strong enough to damage buildings across much of the central U.S. today.

9.1-9.3: Quake that caused the 2004 Indian Ocean tsunami, powerful enough to vibrate the planet.

9.5: Largest earthquake ever recorded, measured in Chile in 1960 and 1.5 times as strong as a 9.3.

Source: Staff Report

At A Glance

Earthquake Readiness

• Before

Earthquakes in Northwest Arkansas are fairly rare, but residents might consider flexible natural gas lines at home and securing upright, heaving furniture to the walls, said Robert McGowen, Benton County emergency director. Families should have plans beforehand on where to meet each other in weather or other emergencies.

• During

If you’re inside, get under a sturdy table or crouch in a corner away from windows and furniture that could fall. If you’re outside, stay away from trees, wires and buildings. Whether you’re indoors or outdoors, stay there: The greatest risk of injury is around building edges and entrances, according to the Federal Emergency Management Agency.

• After

If indoors, get outside carefully. Keep an eye out for fires and broken objects.

Source: Staff Report

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