Reviewed by USGSNew Zealand79y ago
M6.4 earthquake 71 km NNE of Amberley, New Zealand
Saturday, May 22, 1948, 19:21:27 UTC · 42.546°S, 173.020°E
A magnitude 6.4 earthquake struck 71 km NNE of Amberley, New Zealand on Saturday, May 22, 1948, 19:21:27 UTC, at a depth of 15.0 km (shallow). It is the strongest earthquake within 300 km since an M6.5 on June 26, 1946.
- Magnitude
- 6.4
- Strong · mw
- Depth
- 15 km
- Shallow
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VII
- Very strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
60 kilotons of TNT
That is about 4 times the Hiroshima bomb. It released about 126 times the energy of a magnitude 5.0.
Tectonic setting
15 km
from the nearest mapped plate boundary, between the Australian 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 13 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.368 km S of Wakefield, New ZealandJune 16, 1929 · 63 km N of this epicenter
- 7.030 km NW of Amberley, New ZealandMarch 9, 1929 · 68 km SW of this epicenter
- 7.025 km SE of Masterton, New ZealandJune 24, 1942 · 280 km NE of this epicenter
- 6.815 km SSE of Levin, New ZealandAugust 1, 1942 · 278 km NE of this epicenter
- 6.535 km NNW of Methven, New ZealandJune 26, 1946 · 156 km SW of this epicenter
- 6.558 km SW of Wakefield, New ZealandJune 22, 1929 · 87 km NW of this epicenter
- 6.386 km NNE of Amberley, New ZealandDecember 25, 1922 · 18 km NE of this epicenter
- 6.351 km SSW of Wakefield, New ZealandJune 22, 1929 · 88 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 7 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 20 recorded deaths. The most severe:
- 1929M7.5
South Island
16 Jun 1929 · 109 km away
17 deathsModerate damage ($1–5M)tsunami
- 1848M6.0
Awatere River, Marlborough
18 Oct 1848 · 127 km away
3 deathstsunami
- 1855M8.0
Wellington,Waiouru,Wanganui,Otaki
23 Jan 1855 · 218 km away
Severe damage ($5–24M)tsunami
- 1848M7.9
N.
15 Oct 1848 · 185 km away
Limited damage (under $1M)tsunami
- 1913M6.8
Tasman Sea
22 Feb 1913 · 150 km away · intensity VIII
Limited damage (under $1M)tsunami
- 1868M7.6
Tasman Sea
18 Oct 1868 · 261 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.