Reviewed by USGSNew Zealand64y ago
M7.3 earthquake in Kermadec Islands, New Zealand
Tuesday, March 26, 1963, 09:48:17 UTC · 29.992°S, 177.675°W
A magnitude 7.3 earthquake struck in Kermadec Islands, New Zealand on Tuesday, March 26, 1963, 09:48:17 UTC, at a depth of 10.0 km (shallow). It is the strongest earthquake within 300 km since an M7.3 on September 14, 1959.
- Magnitude
- 7.3
- Major · mw
- Depth
- 10 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: 200 km aftershock search area
In context
How big was it, and why here?
Energy released
1.3 megatons of TNT
That is about 89 times the Hiroshima bomb. It released about 2,818 times the energy of a magnitude 5.0.
Tectonic setting
114 km
from the nearest mapped plate boundary, between the Kermadec and Pacific plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
10 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 200 km
USGS lists 5 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.6 on March 31, 1963. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 6.2Kermadec Islands, New Zealand64y ago · 25 km SW of this epicenter
- 6.6Kermadec Islands, New Zealand64y ago · 6 km E of this epicenter
- 5.8Kermadec Islands, New Zealand64y ago · 31 km E of this epicenter
- 5.3Kermadec Islands, New Zealand64y ago · 20 km SW of this epicenter
- 6.5Kermadec Islands, New Zealand64y ago · 35 km W of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 127 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.21917 Kermadec Islands, New Zealand EarthquakeMay 1, 1917 · 166 km SE of this epicenter
- 7.5Kermadec Islands regionFebruary 27, 1955 · 273 km NE of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 22 km NW of this epicenter
- 7.3Kermadec Islands regionSeptember 14, 1959 · 136 km N of this epicenter
- 7.2Kermadec Islands, New ZealandAugust 2, 1941 · 25 km N of this epicenter
- 7.2Kermadec Islands, New ZealandApril 17, 1919 · 72 km SW of this epicenter
- 7.1Kermadec Islands, New ZealandJune 29, 1910 · 116 km SE of this epicenter
- 7.1Kermadec Islands, New ZealandSeptember 16, 1941 · 99 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1917M8.0
Kermadec Islands
1 May 1917 · 110 km away
tsunami
- 1959M7.7
Kermadec Islands
14 Sep 1959 · 178 km away
- 1943M7.6
S Of
14 Sep 1943 · 65 km away
- 1917M7.5
S Of
16 Nov 1917 · 112 km away
tsunami
- 1961M7.5
Kermadec Islands
7 Mar 1961 · 269 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.