Richter magnitude scale can vary widely. Minor earthquakes occur every day and hour. On the other hand, great earthquakes occur once a year, on average. The largest recorded earthquake was the Great Chilean earthquake of May 22, 1960, which had a magnitude of 9.5 on the moment magnitude scale. The larger the magnitude, the less frequently the earthquake happens. Seismologist Susan Hough has suggested that 10 may represent a very approximate upper limit, as the effect if the largest known continuous belt of faults ruptured together (along the Pacific coast of the Americas). These formulae for Richter magnitude formula_25 are alternatives to using
Orders of magnitude (length) (10 m or 1.1 billion light-years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depends on the cosmological models used. To help compare different orders of magnitude, this section lists distances starting at 100 Ym (10 m or 11 billion light years). At this scale, expansion of the universe becomes significant. Distance of these objects are derived from their measured redshifts, which depend on the cosmological models used. Distances longer than 100 Ym Orders of magnitude (length) The following are examples of orders of magnitude for different lengths.