Alpine Fault
South Island, New Zealand · continental transform · 1115.4 km of mapped active fault in 6 traces
background as of 7 November 2026.
consistent with baseline
| Window | the last 30.0 days |
|---|---|
| Earthquakes counted | 0 at M4.5 or above |
| Expected in that window | 0.47 |
What this system normally does
From 1995 to 2025 the catalogue holds 170 earthquakes of M4.5 or larger attributable to this system: about 5.67 a year. That figure is what "elevated" on this page is measured against.
The fault itself
| Mapped length | 1115.4 km |
|---|---|
| Traces | 6 |
| Tectonic setting | continental transform |
| Slip types | Dextral, Dextral-Reverse |
| Depth attributed to it | down to 50.0 km |
| Extent | -45.91 to -41.80 latitude, 165.72 to 172.88 longitude |
Recorded history
NOAA's hazard records hold 6 significant earthquakes and 2 tsunamis attributed to this system since 1826.
The deadliest was the 16 June 1929 magnitude 7.5 earthquake (New Zealand: South Island), which killed 17 people.
The strongest earthquake on record here was magnitude 8.0, on 1826 (New Zealand: Fjordland).
The most recent entry is the 15 July 2009 magnitude 7.8 earthquake (New Zealand: off West Coast of South Island).
| Date | What | Where | Toll |
|---|---|---|---|
| 16 June 1929 | magnitude 7.5 earthquake | New Zealand: South Island | 17 dead, damage $1 to 5 million |
| 1826 | magnitude 8.0 earthquake | New Zealand: Fjordland | - |
| 15 July 2009 | magnitude 7.8 earthquake | New Zealand: off West Coast of South Island | damage under $1 million |
| 21 August 2003 | magnitude 7.2 earthquake | New Zealand: Dunedin, Invercargill, Te Anau, Fiordland | damage under $1 million |
| 15 October 2007 | magnitude 6.8 earthquake | New Zealand: South Island: Fiordland | damage under $1 million |
| 18 June 1994 | magnitude 6.8 earthquake | New Zealand: South Island: Christchurch | damage under $1 million |
| 21 August 2003 | tsunami (waves to 4 m) | South Island | damage under $1 million |
| 15 July 2009 | tsunami (waves to 0.5 m) | off West Coast of South Island | damage under $1 million |
A dash means NOAA recorded no number, not that nobody died. Older entries are fewer because fewer were written down, not because less happened.
Recorded history: NOAA NCEI hazard databases, public domain, retrieved 2026-10-22.
Published rupture probability
Howarth et al., Te Herenga Waka Victoria University of Wellington, via AF8 publishes a probability for this system. It is their figure, not ours:
| Probability | 75% |
|---|---|
| For an earthquake of | M7.0 or larger |
| Within | 50 years |
| As of | 2021 |
A published study rather than an official national forecast. The same work puts the chance that such an event is M8 or larger at 82 percent.
Read the issuer's own publication
Who to listen to if you live here
Get Ready (New Zealand NEMA) is the agency that tells people on this system what to do. https://getready.govt.nz/emergency/earthquakes/ (in English)
Where these numbers come from
Fault geometry, length and segment counts: GEM Global Active Faults Database (GEM GAF-DB), GEM Foundation, https://github.com/GEMScienceTools/gem-global-active-faults Licence: CC-BY-SA-4.0. Figures derived from it here are offered under the same licence. Earthquake counts, magnitudes and depths: United States Geological Survey, public domain. The activity judgement is ours, computed from those two inputs, and is not a statement by either agency.