Reviewed by USGSNew Zealand52y ago
M4.8 earthquake in Kermadec Islands, New Zealand
Sunday, July 28, 1974, 07:52:59 UTC · 29.152°S, 177.677°W
A magnitude 4.8 earthquake struck in Kermadec Islands, New Zealand on Sunday, July 28, 1974, 07:52:59 UTC, at a depth of 63.0 km (shallow). It is the strongest earthquake within 300 km since an M5.8 on July 24, 1974.
- Magnitude
- 4.8
- Light · mb
- Depth
- 63 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 earthquake
In context
How big was it, and why here?
Energy released
239 tons of TNT
That is about 1/63 of the Hiroshima bomb. A magnitude 5.0 releases about 2 times more energy.
Tectonic setting
111 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
63 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 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 236 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 · 248 km SE of this epicenter
- 7.5Kermadec Islands regionFebruary 27, 1955 · 222 km NE of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 79 km S of this epicenter
- 7.3Kermadec Islands regionSeptember 14, 1959 · 57 km NE of this epicenter
- 7.3Kermadec Islands, New ZealandMarch 26, 1963 · 93 km S of this epicenter
- 7.3Kermadec Islands, New ZealandJuly 25, 1968 · 189 km S of this epicenter
- 7.2Kermadec Islands regionJuly 2, 1974 · 168 km E of this epicenter
- 7.2Kermadec Islands, New ZealandAugust 2, 1941 · 70 km S 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 · 196 km away
Limited damage (under $1M)tsunami
- 1917M8.0
Kermadec Islands
1 May 1917 · 66 km away
tsunami
- 1955M7.8
Kermadec Islands
27 Feb 1955 · 248 km away
- 1959M7.7
Kermadec Islands
14 Sep 1959 · 98 km away
- 1943M7.6
S Of
14 Sep 1943 · 115 km away
- 1917M7.5
S Of
16 Nov 1917 · 24 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.