Reviewed by USGSNew Zealand52y ago
M4.5 earthquake in Kermadec Islands, New Zealand
Thursday, July 18, 1974, 14:27:12 UTC · 29.875°S, 177.679°W
A magnitude 4.5 earthquake struck in Kermadec Islands, New Zealand on Thursday, July 18, 1974, 14:27:12 UTC, at a depth of 654.0 km (deep). It is the strongest earthquake within 300 km since an M4.9 on July 18, 1974.
- Magnitude
- 4.5
- Light · mb
- Depth
- 654 km
- Deep
- 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
85 tons of TNT
That is about 1/178 of the Hiroshima bomb. A magnitude 5.0 releases about 6 times more energy.
Tectonic setting
120 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: deep
654 km
Deep earthquakes (over 300 km) happen deep inside subducting plates. They rarely cause damage, but can be felt faintly over very large distances.
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 50 km
USGS has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 242 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 · 177 km SE of this epicenter
- 7.5Kermadec Islands regionFebruary 27, 1955 · 265 km NE of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 16 km W of this epicenter
- 7.3Kermadec Islands regionSeptember 14, 1959 · 124 km N of this epicenter
- 7.3Kermadec Islands, New ZealandMarch 26, 1963 · 13 km S of this epicenter
- 7.3Kermadec Islands, New ZealandJuly 25, 1968 · 112 km SW of this epicenter
- 7.2Kermadec Islands regionJuly 2, 1974 · 189 km NE of this epicenter
- 7.2Kermadec Islands, New ZealandAugust 2, 1941 · 13 km NE 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. The most severe:
- 1968M7.3
S Of, Raoul
25 Jul 1968 · 124 km away
Limited damage (under $1M)tsunami
- 1917M8.0
Kermadec Islands
1 May 1917 · 100 km away
tsunami
- 1955M7.8
Kermadec Islands
27 Feb 1955 · 297 km away
- 1959M7.7
Kermadec Islands
14 Sep 1959 · 166 km away
- 1943M7.6
S Of
14 Sep 1943 · 67 km away
- 1917M7.5
S Of
16 Nov 1917 · 99 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.