Litchfield, N.J.; Berryman, K.R. 2013 Times and distances between events from selected global earthquake sequences; comparison with the 2010-2012 Canterbury earthquake sequence. Lower Hutt, N.Z.: GNS Science. GNS Science report 2012/43 20 p.
Abstract: The lengths of times (days) and distances (km) between large events in selected global earthquake sequences are summarised and compared with the 2010-2012 (and ongoing) Canterbury earthquake sequence. The motivation was to address the question “Is the Canterbury sequence typical?” The global earthquake sequence inter-event times and distances were compiled from published scientific papers and maps. The selection of the earthquake sequences is not statistically robust, but instead is simply a set of examples that we consider may have some similarities with the tectonic setting in which occurred the Canterbury earthquake sequence. The sequences reviewed are the pre-instrumental 1811-1812 New Madrid, 1876 Oamaru, 1883-1892 Tasmania, and 1929-1968 Buller sequences, and the instrumentally-recorded 1988 Tennant Creek, and 1992-1999 Landers earthquake sequences. Inter-event times for the global earthquake sequences vary from 0 to 14,192 days (39 years) and inter-event distances from 3 to 110 km respectively. This wide variation suggests that there is no such thing as a typical earthquake sequence in terms of inter-event times and distances in low strain rate zones such as Canterbury. The Canterbury earthquake sequence inter-event times and distances are 171, 111, and 193 days and 42, 5, and 5 km respectively. These are clearly within, but are generally at the shorter end of the global sequence ranges, which suggests that the Canterbury sequence is not atypical. Plots of inter-event times and distances against magnitude are not well correlated, indicating earthquake magnitude cannot be used as an indication of likely times and distances to subsequent earthquakes. Instead, earthquake sequences are more likely to reflect the state of stress on faults in surrounding areas, such that earthquakes are triggered only if faults are ready to fail. (auth)