A minor earthquake shook pictures off walls in two central Oklahoma communities early today but experts said there was no connection with a potential major quake on the New Madrid Fault. The Oklahoma Geological Survey said the quake registered 3.6 on the Richter scale of ground movement. A quake of magnitude 3.5 can cause slight damage. A quake of magnitude 2 is the smallest normally felt by humans. The National Weather Service said it had received reports of a tremor about 5:45 a.m. that was felt in Rush Springs, about 40 miles southwest of Oklahoma City, and Lindsay, about 28 miles south of Oklahoma City. The geological survey said the quake was centered 5 miles north of Lindsay. ``Police departments in those areas indicate that pictures fell from walls, objects were knocked off tables and out of cabinets and many residents were awakened,'' the weather service said in a statement. Geological survey director Charles Mankin said earthquakes are common in Oklahoma, with a couple a week detected by sensitive seismographs. ``We rarely record them as high as 3.6,'' he said. ``But a small earthquake in that area is not unusual.'' Larry Thompson of KBLP radio in Lindsay said the station was flooded with calls after the tremor was felt. At the police department, dispatcher Lois Knapp said the shaking lasted about two seconds. ``This police department is cement and brick and rock, and it moved,'' she said. There has been increased concern about a Midwestern earthquake since a New Mexico climatologist projected that there could be a major one in early December along the New Madrid Fault, which runs from Cairo, Ill., to Marked Tree, Ark. The projection, based on the fact that tidal forces will be particularly strong early next month, is disputed by most scientists. Mankin said there was no link between today's quake and the New Madrid Fault. ``Most of the earthquakes in Oklahoma we have not been able to relate to faults,`` Mankin said. ``They're very shallow earthquakes and we know they're from some ground adjustment, obviously, but we can't relate them to some fault.'' In 1811-1812, a series of quakes estimated at up to 8 on the Richter scale struck the New Madrid Fault, ringing church bells in Washington, D.C., more than 850 miles away. Jim Lawson, chief geophysicist at the geological survey, said earlier this week that even if a major quake occurred along the New Madrid Fault, its effect in Oklahoma would be negligible.
