Reviewed by USGS40y ago
M5.0 earthquake in Kermadec Islands region
Friday, December 26, 1986, 02:41:18 UTC · 28.874°S, 176.990°W
A magnitude 5.0 earthquake struck in Kermadec Islands region on Friday, December 26, 1986, 02:41:18 UTC, at a depth of 29.9 km (shallow). It is the strongest earthquake within 300 km since an M6.5 on December 21, 1986.
- Magnitude
- 5.0
- Moderate · mb
- Depth
- 30 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
477 tons of TNT
That is about 1/32 of the Hiroshima bomb. Each whole step in magnitude is about 32 times more energy.
Tectonic setting
91 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
30 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 3 M2.5+ earthquakes within 75 km in the following 30 days; the largest was M5.7 on January 13, 1987. 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 835 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 · 260 km S of this epicenter
- 8.01976 Kermadec Islands, New Zealand EarthquakeJanuary 14, 1976 · 82 km NW of this epicenter
- 7.7Kermadec Islands regionOctober 20, 1986 · 104 km NE of this epicenter
- 7.5Kermadec Islands regionFebruary 27, 1955 · 148 km NE of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 136 km SW of this epicenter
- 7.3Kermadec Islands regionSeptember 14, 1959 · 22 km W of this epicenter
- 7.3Kermadec Islands, New ZealandMarch 26, 1963 · 141 km SW of this epicenter
- 7.3Kermadec Islands, New ZealandJuly 25, 1968 · 241 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 11 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1986M8.1
Raoul
20 Oct 1986 · 104 km away
Limited damage (under $1M)tsunami
- 1976M7.9
Kermadec Islands
14 Jan 1976 · 56 km away
Limited damage (under $1M)tsunami
- 1968M7.3
S Of, Raoul
25 Jul 1968 · 254 km away
Limited damage (under $1M)tsunami
- 1917M8.0
Kermadec Islands
1 May 1917 · 36 km away
tsunami
- 1955M7.8
Kermadec Islands
27 Feb 1955 · 175 km away
- 1976M7.8
Kermadec Islands
14 Jan 1976 · 119 km away · intensity VIII
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.