Reviewed by USGS18y ago
M6.8 earthquake in Kermadec Islands region
Tuesday, December 9, 2008, 06:23:59 UTC · 31.232°S, 176.924°W
A magnitude 6.8 earthquake struck in Kermadec Islands region on Tuesday, December 9, 2008, 06:23:59 UTC, at a depth of 18.0 km (shallow). It is the strongest earthquake within 300 km since an M7.0 on September 29, 2008.
- Magnitude
- 6.8
- Strong · mwc
- Depth
- 18 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: 100 km aftershock search area
In context
How big was it, and why here?
Energy released
239 kilotons of TNT
That is about 16 times the Hiroshima bomb. It released about 501 times the energy of a magnitude 5.0.
Tectonic setting
8 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
18 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 100 km
USGS lists 56 M2.5+ earthquakes within 100 km in the following 30 days; the largest was M5.1 on December 16, 2008. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.3Kermadec Islands region18y ago · 91 km N of this epicenter
- 4.4Kermadec Islands region18y ago · 25 km NE of this epicenter
- 4.2Kermadec Islands region18y ago · 73 km NE of this epicenter
- 4.2Kermadec Islands region18y ago · 80 km NE of this epicenter
- 3.9Kermadec Islands region18y ago · 32 km SE of this epicenter
- 5.0Kermadec Islands region18y ago · 87 km N of this epicenter
- 4.3Kermadec Islands region18y ago · 87 km N of this epicenter
- 4.5Kermadec Islands region18y ago · 41 km NE of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 1,571 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 · 26 km E of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 177 km NW of this epicenter
- 7.4Kermadec Islands regionMay 16, 2006 · 235 km W of this epicenter
- 7.3Kermadec Islands regionSeptember 14, 1959 · 267 km N of this epicenter
- 7.3Kermadec Islands, New ZealandMarch 26, 1963 · 155 km NW of this epicenter
- 7.3Kermadec Islands, New ZealandJuly 25, 1968 · 126 km W of this epicenter
- 7.2Kermadec Islands regionJuly 2, 1974 · 257 km N of this epicenter
- 7.2Kermadec Islands, New ZealandFebruary 9, 1978 · 74 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 8 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1976M7.9
Kermadec Islands
14 Jan 1976 · 232 km away
Limited damage (under $1M)tsunami
- 1968M7.3
S Of, Raoul
25 Jul 1968 · 149 km away
Limited damage (under $1M)tsunami
- 1917M8.0
Kermadec Islands
1 May 1917 · 226 km away
tsunami
- 1976M7.8
Kermadec Islands
14 Jan 1976 · 148 km away · intensity VIII
- 1978M7.7
S Of
9 Feb 1978 · 74 km away
- 1943M7.6
S Of
14 Sep 1943 · 137 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.