Reviewed by USGS29y ago
M4.6 earthquake in Kermadec Islands region
Sunday, May 18, 1997, 03:00:06 UTC · 31.674°S, 178.758°W
A magnitude 4.6 earthquake struck in Kermadec Islands region on Sunday, May 18, 1997, 03:00:06 UTC, at a depth of 33.0 km (shallow). It is the strongest earthquake within 300 km since an M4.6 on May 15, 1997.
- Magnitude
- 4.6
- Light · mb
- 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: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
120 tons of TNT
That is about 1/126 of the Hiroshima bomb. A magnitude 5.0 releases about 4 times more energy.
Tectonic setting
81 km
from the nearest mapped plate boundary, between the Kermadec and Australian 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 50 km
USGS lists 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.5 on May 25, 1997. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 1,125 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 · 207 km E of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 221 km NE of this epicenter
- 7.3Kermadec Islands, New ZealandMarch 26, 1963 · 214 km NE of this epicenter
- 7.3Kermadec Islands, New ZealandJuly 25, 1968 · 113 km NE of this epicenter
- 7.2Kermadec Islands, New ZealandFebruary 9, 1978 · 173 km NE of this epicenter
- 7.2Kermadec Islands, New ZealandJuly 3, 1995 · 296 km NE of this epicenter
- 7.2Kermadec Islands, New ZealandAugust 2, 1941 · 238 km NE of this epicenter
- 7.2Kermadec Islands, New ZealandApril 17, 1919 · 142 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 4 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 · 103 km away
Limited damage (under $1M)tsunami
- 1976M7.8
Kermadec Islands
14 Jan 1976 · 244 km away · intensity VIII
- 1978M7.7
S Of
9 Feb 1978 · 173 km away
- 1943M7.6
S Of
14 Sep 1943 · 251 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.