Richter magnitude scale from it empirically as a quantity without units, just a number designed to conform to the formula_3 scale. A spectral analysis is required to obtain formula_12, whereas the other magnitudes are derived from a simple measurement of the amplitude of a specifically defined wave. All scales, except formula_5, saturate for large earthquakes, meaning they are based on the amplitudes of waves which have a wavelength shorter than the rupture length of the earthquakes. These short waves (high frequency waves) are too short a yardstick to measure the extent of the event. The resulting effective upper limit of measurement for formula_17
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.