3.9 earthquake in Oklahoma?

[DVS]

Just a few minutes ago, they said there was a 3.9 magnitude earthquake with the epicenter in Sparks, Oklahoma. I know 3.9 isn't that large, but we're talking about the center of the US. I know the New Madrid fault that hasn't moved for many years that's in southern Missouri, but I didn't know about one in Oklahoma.

Is there anybody down there to give some info on the quake?

http://kwtv.images.worldnow.com/images/18274264_BG1.JPG
A 3.9 magnitude earthquake was recorded near Sparks, Oklahoma, Thursday afternoon.
SPARKS, Oklahoma -

A 3.9 magnitude earthquake was recorded near Sparks, Oklahoma, Thursday afternoon.

According to the U.S. Geological Survey, the earthquake was recorded at around 4:14 p.m. Wednesday. Its epicenter was about five miles south southeast of Sparks, six miles northwest of Prague, and 43 miles east of Oklahoma City.

It was about four miles deep.

No injuries or damage were immediately reported in this earthquake.

 

[Shankara20]

Is there anybody down there to give some info on the quake?

Nothing going on here in Wichita, Ks about an hour north of the Ok boarder. Might be some local news at 10:00 pm.

I wonder about fracking as a cause...

 

[DVS]

I saw nothing on the news about it in my area. I'd say this is big news just because Oklahoma had a rather large one last year. The mid-west is an area that doesn't have large earthquakes for many years. Are we now starting to have them?

I've checked and while we have had about 4000 relatively minor earthquakes reported around the New Madrid fault since 1974, none of them really amounted to much. But, in the years of 1811 and 1812, we had four that were rather major in size. If my history is correct, after one of those earthquakes, the Mississippi river was said to flow backwards for a period of time.

While the recent quake in Oklahoma doesn't seem to be news worthy for anybody except the town of Sparks, I thought it interesting to note that the last major earthquakes in our area were just over 200 years ago. I don't know if this has any relevance in earthquake logic, but I thought it was maybe something to look forward to. Isn't the world suppose to end in December 2012? Maybe there's some truth to that calendar thing after all.

The 1811–1812 earthquakes...

December 16, 1811, 0815 UTC (2:15 a.m.); (M ~7.2 – 8.1) epicenter in northeast Arkansas. It caused only slight damage to man-made structures, mainly because of the sparse population in the epicentral area. The future location of Memphis, Tennessee experienced level IX shaking on the Mercalli intensity scale. A seismic seiche propagated upriver, and Little Prairie (a village that was on the site of the former Fort San Fernando, near the site of present-day Caruthersville, Missouri) was heavily damaged by soil liquefaction.

December 16, 1811, 1415 UTC (8:15 a.m.); (M ~7.2–8.1) epicenter in northeast Arkansas. This shock followed the first earthquake by six hours and was similar in intensity.

January 23, 1812, 1500 UTC (9 a.m.); (M ~7.0–7.8) epicenter in the Missouri Boot heel. The meizoseismal area was characterized by general ground warping, ejections, fissuring, severe landslides, and caving of stream banks. Johnson and Schweig attributed this earthquake to a rupture on the New Madrid North Fault. This may have placed strain on the Reelfoot Fault.

February 7, 1812, 0945 UTC (4:45 a.m.); (M ~7.4–8.0) epicenter near New Madrid, Missouri. New Madrid was destroyed. At St. Louis, Missouri, many houses were severely damaged, and their chimneys were toppled. This shock was definitively attributed to the Reelfoot Fault by Johnston and Schweig. Uplift along a segment of this reverse fault created temporary waterfalls on the Mississippi at Kentucky Bend, created waves that propagated upstream, and caused the formation of Reelfoot Lake by obstructing streams in what is now Lake County, Tennessee.

Susan Hough, a seismologist of the United States Geological Survey (USGS), has recently estimated the earthquakes' magnitudes as "right around magnitude 7. Possibly a bit below, possibly a bit above, but not as big as 7.5."