4.8 quake shakes Kansas, Oklahoma, Arkansas

An earthquake with a preliminary magnitude of 4.8 shook parts of Kansas and Oklahoma on Wednesday, the largest since a series of temblors began rattling Kansas a little more than a year ago. (Nov. 13) AP

A magnitude-4.8 earthquake Wednesday shook up parts of Kansas, Oklahoma and Arkansas, the strongest of eight temblors that rattled the seismically active region over 24 hours.

The moderately strong quake, which was relatively shallow at 3.4 miles deep, struck at 3:40 p.m. CT near the Sumner County community of Conway Springs, about 30 miles southwest of Wichita along the Oklahoma border, the U.S. Geological Survey said. The jolt was felt across much of the state and as far away as Tulsa, Okla., about 170 miles away. Some Arkansas residents also reported the shaking.

Some structural damage was reported, mostly in nearby Milan, Kan., but no injuries. One Sedgwick County resident told a 911 dispatcher that the quake "moved me and my recliner about eight inches across the floor."

The region is at the heart of the state's mini oil-and-gas boom involving hydraulic fracturing, commonly known as fracking, and state and federal agencies are trying to determine whether the controversial technique is responsible for a significant increase in earthquakes over the past two years. Energy companies deny the connection, saying the state has always had earthquakes.

Just hours before Wednesday's jolt, Kansas Gov. Sam Brownback announced that the state would deploy six portable monitors to track the upswing in ground movement in Sumner County and its fracking neighbors Harper and Barber counties. The $85,000 network, which was recommended in September by a task force Brownback appointed to study the escalating seismic activity, is expected to be operating early next year.

Before Wednesday's quake, Kansas had experienced 93 earthquakes this year, the U.S. Geological Survey reported. They ranged from magnitude 1.3 to 4.3, and nearly all occurred in Sumner, Harper and Barber counties. A 4.1 quake hit the area in September.

Tuesday, a magnitude-2.6 quake rattled Anthony, Kan., in Harper County.

The state's strongest earthquake was magnitude 5.1, striking Manhattan in 1867.

Across the border, meanwhile, six earthquakes registering between magnitude 2.6 and 2.9 jiggled north-central Oklahoma on Wednesday.