The Alpine Fault is a geological fault that runs almost the entire length of New Zealand's South Island, being about .The length quoted in the article introduction at 480 km was noted on article review in May 2023 to be discordant with the length presently quoted in the reference used which is of 600 km. This source, while not an original academic work is an respected source so length was corrected back after external validation. It is quite possible that the reference was updated after the access date of 2018-12-31 or that the 480 km figure is actually the length of off set of the fault inserted in easy to make error, and indeed constrains the minimum length of the fault. It was further noted that another non academic reference to length of the fault used in the article later claimed a fault length of 850 km. This source, when checked was actually effectively a press statement on research findings, so not peer reviewed and is likely from Nathan 2011 as source. It has been corrected too with context. However Berryman's group started using a 800 km figure in their 2012 academic work, up from Berryman et al. (1992) which gave a 650km length including the Wairau Fault which many workers do not include in the fault length. There is no evidence yet of full rupture including the Wairau Fault (see article). There is evidence for off shore full length fault rupture however as in the 1717 event. The 800 km length includes the Wairau Fault and assumes the off shore portion ends just south of Fiordland. The length of the fault will depend upon how much if any of the southern off shore portion is included or if the Wairau Fault is added. The GNS New Zealand Active Fault database maps about 520 km of fault on land or if the fault was a straight line end to end about 500 km. The total length of the South Island is about 800km for reference. Academic work on the fault does not always state its total length. long, and forms the boundary between the Pacific Plate and the Indo-Australian Plate. The Southern Alps have been uplifted on the fault over the last 12 million years in a series of earthquakes. However, most of the motion on the fault is strike-slip (side to side), with the Tasman district and West Coast moving north and Canterbury and Otago moving south. The average slip rates in the fault's central region are about a year, very fast by global standards. The last major earthquake on the Alpine Fault was in about 1717 AD with a great earthquake magnitude of . The probability of another one occurring within the next 50 years is estimated at about 75 percent.
