Seismic magnitude scales earthquakes can differ by as much as 1.4 units. Despite the usefulness of the scale, it is not generally used due to difficulties in estimating the radiated seismic energy. K (from the Russian word класс, "class", in the sense of a category) is a measure of earthquake magnitude in the "energy class" or "K-class" system, developed in 1955 by Soviet seismologists in the remote Garm (Tadjikistan) region of Central Asia; in revised form it is still used for local and regional quakes in many states formerly aligned with the Soviet Union (including Cuba). Based on seismic energy (K = log
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