Reviewed by USGS96y ago
M6.2 earthquake off the east coast of the North Island of New Zealand
Sunday, March 8, 1931, 11:50:43 UTC · 39.344°S, 177.348°E
A magnitude 6.2 earthquake struck off the east coast of the North Island of New Zealand on Sunday, March 8, 1931, 11:50:43 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M7.3 on February 13, 1931.
- Magnitude
- 6.2
- Strong · mw
- Depth
- 35 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- —
- No ShakeMap
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquake
In context
How big was it, and why here?
Energy released
33 kilotons of TNT
That is about 2 times the Hiroshima bomb. It released about 70 times the energy of a magnitude 5.0.
Tectonic setting
132 km
from the nearest mapped plate boundary, between the Kermadec and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
35 km
Shallow earthquakes (under 70 km) produce the strongest surface shaking for their size, so they are the ones most likely to cause damage near the epicenter.
Did You Feel It?
Where it was felt
No “Did You Feel It?” reports have been published for this event yet. If you felt it, you can add your report on the USGS website.
I felt it — report to USGS ↗USGS PAGER estimate
Who was exposed to shaking
USGS publishes PAGER impact estimates for significant earthquakes, usually within an hour. No PAGER estimate is available for this event.
After the main event
Aftershocks within 100 km
USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 16 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.447 km WSW of Hastings, New ZealandFebruary 2, 1931 · 99 km SW of this epicenter
- 7.340 km E of Waiouru, New ZealandFebruary 13, 1931 · 105 km W of this epicenter
- 7.044 km N of Whakatane, New ZealandNovember 22, 1914 · 202 km N of this epicenter
- 6.856 km SSE of Castlepoint, New ZealandAugust 5, 1917 · 239 km S of this epicenter
- 6.75 km SSW of Hastings, New ZealandJune 28, 1921 · 58 km SW of this epicenter
- 6.748 km ENE of Opotiki, New ZealandOctober 6, 1914 · 164 km N of this epicenter
- 6.4off the east coast of the North Island of New ZealandFebruary 8, 1931 · 41 km S of this epicenter
- 6.4224 km E of Gisborne, New ZealandOctober 28, 1914 · 287 km E of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 12 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 262 recorded deaths. The most severe:
- 1931M7.7
Hawke Bay
2 Feb 1931 · 123 km away · intensity IX
261 deaths$25 million damagetsunami
- 1914
North Island
6 Oct 1914 · 187 km away · intensity VIII
1 deathModerate damage ($1–5M)tsunami
- 1855M8.0
Wellington,Waiouru,Wanganui,Otaki
23 Jan 1855 · 291 km away
Severe damage ($5–24M)tsunami
- 1843M7.5
Wanganui
8 Jul 1843 · 210 km away
tsunami
- 1904M7.5
E Of North Island
8 Aug 1904 · 132 km away
tsunami
- 1931M7.1
N
13 Feb 1931 · 35 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.