Reviewed by USGSNew Zealand96y ago
M6.1 earthquake 84 km SSE of Wairoa, New Zealand
Wednesday, May 6, 1931, 14:55:50 UTC · 39.671°S, 177.899°E
A magnitude 6.1 earthquake struck 84 km SSE of Wairoa, New Zealand on Wednesday, May 6, 1931, 14:55:50 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M6.5 on April 22, 1931.
- Magnitude
- 6.1
- Strong · mw
- Depth
- 15 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
19 kilotons of TNT
That is about the energy of the Hiroshima bomb. It released about 40 times the energy of a magnitude 5.0.
Tectonic setting
86 km
from the nearest mapped plate boundary, between the Kermadec and Pacific plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
15 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 19 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 · 136 km W of this epicenter
- 7.340 km E of Waiouru, New ZealandFebruary 13, 1931 · 154 km W of this epicenter
- 7.044 km N of Whakatane, New ZealandNovember 22, 1914 · 250 km N of this epicenter
- 6.9144 km SE of Waipawa, New ZealandAugust 8, 1904 · 291 km S of this epicenter
- 6.856 km SSE of Castlepoint, New ZealandAugust 5, 1917 · 226 km SW of this epicenter
- 6.75 km SSW of Hastings, New ZealandJune 28, 1921 · 91 km W of this epicenter
- 6.748 km ENE of Opotiki, New ZealandOctober 6, 1914 · 195 km N of this epicenter
- 6.5105 km SSE of Hastings, New ZealandApril 22, 1931 · 93 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 11 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 · 161 km away · intensity IX
261 deaths$25 million damagetsunami
- 1914
North Island
6 Oct 1914 · 210 km away · intensity VIII
1 deathModerate damage ($1–5M)tsunami
- 1843M7.5
Wanganui
8 Jul 1843 · 249 km away
tsunami
- 1904M7.5
E Of North Island
8 Aug 1904 · 120 km away
tsunami
- 1931M7.1
N
13 Feb 1931 · 79 km away
tsunami
- 1880M7.0
Gisborne
8 Sep 1880 · 123 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.