M 7.0 - 19 km NE of Methven, New Zealand

Tectonic Summary

The September 3, 2010, M 7.0 South Island, New Zealand earthquake occurred as a result of shallow strike-slip faulting within the crust of the Pacific plate, near the eastern foothills of the Southern Alps at the western edge of the Canterbury Plains. The earthquake struck approximately 50 km to the west-northwest of Christchurch, the largest population center in the region, and about 80-90 km to the south and east of the current expression of the Australia-Pacific plate boundary through the island (the Alpine and Hope faults). Focal mechanism solutions indicate that rupture occurred on either a right-lateral west-striking fault or a left-lateral south-striking fault. At the location of the earthquake, the Pacific and Australia plates accommodate about 35 mm/yr of relative motion. The earthquake, though removed from the plate boundary itself, likely reflects right-lateral motion on one of a number of regional faults related to the overall relative motion of these plates and may be related to the overall southern propagation of the Marlborough fault system in recent geologic time. Finite-fault modeling of globally distributed seismic data and geological field mapping have since confirmed that the earthquake occurred on a series of right-lateral faults.

The September 3, 2010, earthquake occurred approximately 50 km to the southeast of a M 7.1, surface-rupturing event in Arthur’s Pass, on March 9, 1929, which caused damage but injured no one. More recently, two earthquakes, M 6.7 and M 5.9, occurred in June 1994 approximately 40 km to the northwest of the 2010 event, but did not cause any known fatalities or significant damage.

Hayes et al. (2016) Tectonic summaries of magnitude 7 and greater earthquakes from 2000 to 2015, USGS Open-File Report 2016-1192. (5.2 MB PDF)