Experts with the U.S. Geological Service report that four earth tremors were felt today in Faulkner County, Arkansas, the largest was a 3.7 magnitude.

The largest earthquake in the most recent swarm of tremors rocking Faulkner
County since last summer registered a 4.7 when it struck near Greenbrier Sunday

Many Arkansans in the immediate area and many miles away reported feeling
it, as well as people in a few other states.

While Arkansas' recorded earthquake history dates back about 200 years to
a major event in the New Madrid seismic zone, the Faulkner County quakes are
not associated with the New Madrid zone and seismologists say there is no history
or research that suggests any cause/effect relationship between the two regions.

Here's a look at the earthquake history in Faulkner County, starting with
the so-called Enola Swarm that began in 1982.

Earthquakes in Faulkner County

Residents of Faulkner County are no strangers to seismic activity. In January
of 1982 a small earthquake that initiated a series of earthquakes jolted
Faulkner County. That swarm of seismic activity lasted for years and produced
over 40,000 earthquakes. The first year of the swarm produced 50 events that
registered magnitudes greater than 2.5.

The largest events of the 1982 Enola swarm were a magnitude 4.5 on January
21, 1982, 4.1 on January 24, 1982 and 4.0 on March 01, 1982. In the last several
years the Enola swarm area has been relatively quiet with only a small occasional

Earthquakes in May 2001 appeared to have occurred in the same area as the
1982 swarm. That started on May 4, 2001with a magnitude 4.4 earthquake that
was followed by more than 2,500 aftershocks in the next two months.

While Sunday's 4.7 outside Greenbrier is big news in modern times, it's a
long way from being the largest earthquake ever to shake Arkansas.