Hikurangi Subduction Margin
New Zealand · subduction interface · 715.4 km of mapped active fault in 15 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 | 0.43 |
What this system normally does
From 1995 to 2025 the catalogue holds 158 earthquakes of M4.5 or larger attributable to this system: about 5.27 a year. That figure is what "elevated" on this page is measured against.
The fault itself
| Mapped length | 715.4 km |
|---|---|
| Traces | 15 |
| Tectonic setting | subduction interface |
| Slip types | Subduction_Thrust |
| Depth attributed to it | down to 700.0 km |
| Extent | -42.06 to -37.16 latitude, 175.50 to 180.00 longitude |
Recorded history
NOAA's hazard records hold 4 significant earthquakes and 4 tsunamis attributed to this system since 1855.
The strongest earthquake on record here was magnitude 8.0, on 23 January 1855 (New Zealand: Wellington, Waiouru, Wanganui, Otaki).
The most recent entry is the 4 March 2021 magnitude 7.3 earthquake (New Zealand: Gisborne).
| Date | What | Where | Toll |
|---|---|---|---|
| 23 January 1855 | magnitude 8.0 earthquake | New Zealand: Wellington, Waiouru, Wanganui, Otaki | damage $5 to 25 million |
| 4 March 2021 | magnitude 7.3 earthquake | New Zealand: Gisborne | - |
| 23 January 1855 | tsunami (waves to 11 m) | Northern Island | damage $5 to 25 million |
| 25 March 1947 | magnitude 7.1 earthquake | New Zealand: off Coast North Island | damage under $1 million |
| 25 March 1947 | tsunami (waves to 10 m) | off Coast of North Island | damage under $1 million |
| 8 September 1880 | magnitude 7.0 earthquake | Gisborne | - |
| 4 March 2021 | tsunami (waves to 0.3 m) | Gisborne | - |
| 8 September 1880 | tsunami | Gisborne | - |
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
GNS Science with Durham and Victoria universities, via East Coast LAB publishes a probability for this system. It is their figure, not ours:
| Probability | 26% |
|---|---|
| For an earthquake of | M8.0 or larger |
| Within | 50 years |
| As of | 2021 |
For the southern end of the margin. A published study rather than an official national forecast.
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.