Wayne County area sees first small quake in almost six months

Southeast Missouri experienced a small earthquake Monday morning that originated a little closer to home than most New Madrid Seismic Zone temblors in recent months.

A 2.8 magnitude event was recorded at 6:44 a.m., about 7 miles east of Williamsville, according to the University of Memphis Center for Earthquake Research and the U.S. Geological Survey. It had a depth of just over 1 kilometer.

Four residents of Williamsville, as well as others in Wappapello and Greenville, had reported to the USGS as of 10 a.m. Monday that they felt the quake.

The most recent local earthquakes recorded by the USGS prior to Monday occurred in January. A 2.3 magnitude event was recorded Jan. 26 about 7 miles east of Greenville, followed by a 2.6 magnitude event Jan. 27 near the same area.

The majority of earthquakes in the past six months have occurred closer to the Missouri-Tennessee border.

A smaller quake, registering at 1.5, occurred at 4:49 a.m. Monday about 4 miles northwest of Ridgely, Tennessee.

NMSZ stations recorded two quakes Monday and about five in the past week.

Since 1974, seismometers, instruments that measure ground shaking, have recorded thousands of small to moderate earthquakes in the NMSZ, according to the USGS.

The NMSZ was the most seismically active area east of the Rocky Mountains until 2014, when the dramatic increase in earthquake rates gave Oklahoma the No. 1 ranking in the contiguous U.S.

The NMSZ is made up of several thrust faults that stretch from Marked Tree, Arkansas, to Cairo, Illinois.

Earthquakes in the central or eastern United States effect much larger areas than earthquakes of similar magnitude in the western United States, the Central United States Earthquake Consortium reports.

For example, the San Francisco, California, earthquake of 1906 (M7.8) was felt 350 miles away in the middle of Nevada, whereas the New Madrid earthquakes of 1811-12 were felt as far away as Connecticut – more than 1,000 miles away.

Scientists say differences in geology east and west of the Rocky Mountains cause this strong contrast.