Moment magnitude scale deal with significant earthquakes larger than . For these events, the official magnitude is the moment magnitude , not Richter's local magnitude . The symbol for the moment magnitude scale is , with the subscript "w" meaning mechanical work accomplished. The moment magnitude is a dimensionless value defined by Hiroo Kanamori as where is the seismic moment in dyne⋅cm (10 N⋅m). The constant values in the equation are chosen to achieve consistency with the magnitude values produced by earlier scales, such as the Local Magnitude and the Surface Wave magnitude. Seismic moment is not a direct measure of energy changes
Frankston, Victoria in or near the suburb of Frankston have occurred in 1932, 1978, 1980, 2009 and 2014. The most recent, on 15 March 2014, measured 2.2 on the Richter magnitude scale. The largest, on 22 September 2009, measured 3.0 on the Richter scale. Olivers Hill is the most prominent elevation in Frankston which rises to 55 metres above sea level (180 feet) at its highest point in the suburb. Its origins date to approximately 415 to 360 million years ago. Its base is Mount Eliza Granite dating from the Devonian period, which was covered in lava tuffs in the Paleogene period.