Moment magnitude scale it is based on, is not measured routinely for smaller quakes. For example, the United States Geological Survey does not use this scale for earthquakes with a magnitude of less than 3.5, which includes the great majority of quakes. Current practice in official earthquake reports is to adopt moment magnitude as the preferred magnitude, i.e., is the official magnitude reported whenever it can be computed. Because seismic moment (, the quantity needed to compute ) is not measured if the earthquake is too small, the reported magnitude for earthquakes smaller than is often Richter's . Popular press reports most often
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.