The Moment Magnitude Scale (abbreviated as MMS, denoted, as MW) is a rating system used by seismologists to calculate the size of an earthquake. The scale rates the earthquake in terms of the total energy let off by the quake. The Moment Magnitude Scale can be used to rate any quake of every size in close proximity or far away. In order to classify a quake scientists must first study that data gathered from the seismographs. The data produced is then used to rate the earthquake.