Reviewed by USGS14y ago
M4.3 earthquake in Kermadec Islands region
Tuesday, December 20, 2011, 07:26:51 UTC · 28.213°S, 177.181°W
A magnitude 4.3 earthquake struck in Kermadec Islands region on Tuesday, December 20, 2011, 07:26:51 UTC, at a depth of 35.0 km (shallow).
- Magnitude
- 4.3
- Light · mb
- Depth
- 35 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
43 tons of TNT
That is about 1/354 of the Hiroshima bomb. A magnitude 5.0 releases about 11 times more energy.
Tectonic setting
125 km
from the nearest mapped plate boundary, between the Kermadec and Pacific plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: shallow
35 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 1,588 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 · 52 km SW of this epicenter
- 7.8south of the Fiji IslandsDecember 9, 2007 · 249 km N of this epicenter
- 7.7Kermadec Islands regionOctober 20, 1986 · 81 km E of this epicenter
- 7.6Kermadec Islands regionJuly 6, 2011 · 169 km SE of this epicenter
- 7.5Kermadec Islands regionFebruary 27, 1955 · 156 km E of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 193 km S of this epicenter
- 7.4Kermadec Islands regionOctober 21, 2011 · 126 km SE of this epicenter
- 7.3Kermadec Islands regionSeptember 14, 1959 · 70 km S of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 14 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1986M8.1
Raoul
20 Oct 1986 · 81 km away
Limited damage (under $1M)tsunami
- 1976M7.9
Kermadec Islands
14 Jan 1976 · 112 km away
Limited damage (under $1M)tsunami
- 1917M8.0
Kermadec Islands
1 May 1917 · 111 km away
tsunami
- 1955M7.8
Kermadec Islands
27 Feb 1955 · 167 km away
- 1976M7.8
Kermadec Islands
14 Jan 1976 · 190 km away · intensity VIII
- 2007M7.8
Kermadec Islands
9 Dec 2007 · 249 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.