Reviewed by USGS52y ago
M7.2 earthquake in Kermadec Islands region
Tuesday, July 2, 1974, 23:26:26 UTC · 29.082°S, 175.954°W
A magnitude 7.2 earthquake struck in Kermadec Islands region on Tuesday, July 2, 1974, 23:26:26 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M7.3 on July 25, 1968.
- Magnitude
- 7.2
- Major · ms
- Depth
- 33 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
951 kilotons of TNT
That is about 63 times the Hiroshima bomb. It released about 1,995 times the energy of a magnitude 5.0.
Tectonic setting
12 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
33 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 16 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M6.6 on July 3, 1974. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.8Kermadec Islands region52y ago · 102 km NW of this epicenter
- 4.8Kermadec Islands, New Zealand52y ago · 168 km W of this epicenter
- 5.1Kermadec Islands region52y ago · 82 km S of this epicenter
- 4.5Kermadec Islands, New Zealand52y ago · 189 km SW of this epicenter
- 4.7Kermadec Islands region52y ago · 35 km W of this epicenter
- 4.6Kermadec Islands region52y ago · 43 km W of this epicenter
- 4.9Kermadec Islands region52y ago · 36 km W of this epicenter
- 5.0Kermadec Islands region52y ago · 59 km SW of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 199 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 · 244 km S of this epicenter
- 7.5Kermadec Islands regionFebruary 27, 1955 · 90 km NE of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 201 km SW of this epicenter
- 7.3Kermadec Islands regionSeptember 14, 1959 · 125 km W of this epicenter
- 7.3Kermadec Islands, New ZealandMarch 26, 1963 · 195 km SW of this epicenter
- 7.3Kermadec Islands, New ZealandJuly 25, 1968 · 285 km SW of this epicenter
- 7.2Kermadec Islands, New ZealandAugust 2, 1941 · 177 km SW of this epicenter
- 7.2Kermadec Islands, New ZealandApril 17, 1919 · 258 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 6 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1917M8.0
Kermadec Islands
1 May 1917 · 102 km away
tsunami
- 1955M7.8
Kermadec Islands
27 Feb 1955 · 128 km away
- 1959M7.7
Kermadec Islands
14 Sep 1959 · 121 km away
- 1943M7.6
S Of
14 Sep 1943 · 144 km away
- 1917M7.5
S Of
16 Nov 1917 · 151 km away
tsunami
- 1961M7.5
Kermadec Islands
7 Mar 1961 · 90 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.