Reviewed by USGSNew Zealand97y ago
M6.0 earthquake 34 km ESE of Napier, New Zealand
Thursday, February 5, 1931, 08:57:09 UTC · 39.579°S, 177.302°E
A magnitude 6.0 earthquake struck 34 km ESE of Napier, New Zealand on Thursday, February 5, 1931, 08:57:09 UTC, at a depth of 35.0 km (shallow). It is the strongest earthquake within 300 km since an M7.4 on February 2, 1931.
- Magnitude
- 6.0
- Moderate · 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 earthquakeDashed circle: 75 km aftershock search area
In context
How big was it, and why here?
Energy released
13 kilotons of TNT
That is about the energy of the Hiroshima bomb. It released about 27 times the energy of a magnitude 5.0.
Tectonic setting
118 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 75 km
USGS lists 1 M2.5+ earthquake within 75 km in the following 30 days; the largest was M6.4 on February 8, 1931. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 13 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 · 86 km W of this epicenter
- 7.044 km N of Whakatane, New ZealandNovember 22, 1914 · 227 km N of this epicenter
- 6.9144 km SE of Waipawa, New ZealandAugust 8, 1904 · 292 km S of this epicenter
- 6.856 km SSE of Castlepoint, New ZealandAugust 5, 1917 · 212 km S of this epicenter
- 6.75 km SSW of Hastings, New ZealandJune 28, 1921 · 42 km W of this epicenter
- 6.748 km ENE of Opotiki, New ZealandOctober 6, 1914 · 190 km N of this epicenter
- 6.4224 km E of Gisborne, New ZealandOctober 28, 1914 · 298 km E of this epicenter
- 6.384 km SSE of Castlepoint, New ZealandSeptember 12, 1919 · 230 km S 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 · 111 km away · intensity IX
261 deaths$25 million damagetsunami
- 1914
North Island
6 Oct 1914 · 213 km away · intensity VIII
1 deathModerate damage ($1–5M)tsunami
- 1855M8.0
Wellington,Waiouru,Wanganui,Otaki
23 Jan 1855 · 269 km away
Severe damage ($5–24M)tsunami
- 1843M7.5
Wanganui
8 Jul 1843 · 200 km away
tsunami
- 1904M7.5
E Of North Island
8 Aug 1904 · 106 km away
tsunami
- 1931M7.1
N
13 Feb 1931 · 27 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.