Randolph, Tennessee in the area since 1974 occurred on August 19, 1994 – the temblor was measured 3.2 on the Richter scale with an epicenter at coordinates , ca. west of Randolph, at a depth of . On January 16, 2009 at 3:09 p.m. local time (21:09 UTC), "a small earthquake shook portions of Tipton County". The earthquake was measured at a magnitude 2.8 on the Richter scale. According to the Center for Earthquake Research and Information (CERI), the epicenter of the temblor was reported to be at coordinates at a depth of . There were no reports of damage caused by
Richter magnitude scale isolated area. Several scales have historically been described as the "Richter scale", especially the "local magnitude" formula_2 and the surface wave formula_3 scale. In addition, the "body wave magnitude", formula_4, and the "moment magnitude", formula_5, abbreviated MMS, have been widely used for decades. A couple of new techniques to measure magnitude are in the development stage by seismologists. All magnitude scales have been designed to give numerically similar results. This goal has been achieved well for formula_2, formula_3, and formula_5. The formula_4 scale gives somewhat different values than the other scales. The reason for so many different ways to measure