Reviewed by USGS40y ago
M5.6 earthquake in Kermadec Islands region
Wednesday, November 12, 1986, 20:54:27 UTC · 28.207°S, 176.630°W
A magnitude 5.6 earthquake struck in Kermadec Islands region on Wednesday, November 12, 1986, 20:54:27 UTC, at a depth of 32.5 km (shallow). It is the strongest earthquake within 300 km since an M5.6 on November 10, 1986.
- Magnitude
- 5.6
- Moderate · mw
- 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: 75 km aftershock search area
In context
How big was it, and why here?
Energy released
4 kilotons of TNT
That is about 1/4 of the Hiroshima bomb. It released about 8 times the energy of a magnitude 5.0.
Tectonic setting
73 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 75 km
USGS lists 4 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M4.7 on December 1, 1986. 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 711 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.01976 Kermadec Islands, New Zealand EarthquakeJanuary 14, 1976 · 103 km W of this epicenter
- 7.7Kermadec Islands regionOctober 20, 1986 · 28 km E of this epicenter
- 7.5Kermadec Islands regionFebruary 27, 1955 · 102 km E of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 217 km SW of this epicenter
- 7.3Kermadec Islands regionSeptember 14, 1959 · 90 km SW of this epicenter
- 7.3Kermadec Islands, New ZealandMarch 26, 1963 · 223 km SW of this epicenter
- 7.3south of the Fiji IslandsJanuary 20, 1970 · 262 km N of this epicenter
- 7.2Kermadec Islands regionJuly 2, 1974 · 118 km SE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 12 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1986M8.1
Raoul
20 Oct 1986 · 28 km away
Limited damage (under $1M)tsunami
- 1976M7.9
Kermadec Islands
14 Jan 1976 · 135 km away
Limited damage (under $1M)tsunami
- 1917M8.0
Kermadec Islands
1 May 1917 · 116 km away
tsunami
- 1955M7.8
Kermadec Islands
27 Feb 1955 · 113 km away
- 1976M7.8
Kermadec Islands
14 Jan 1976 · 199 km away · intensity VIII
- 1959M7.7
Kermadec Islands
14 Sep 1959 · 49 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.