Reviewed by USGS15y ago
M4.5 earthquake in Kermadec Islands region
Sunday, October 30, 2011, 09:46:18 UTC · 28.218°S, 176.107°W
A magnitude 4.5 earthquake struck in Kermadec Islands region on Sunday, October 30, 2011, 09:46:18 UTC, at a depth of 46.7 km (shallow). It is the strongest earthquake within 300 km since an M4.5 on October 28, 2011.
- Magnitude
- 4.5
- Light · mb
- Depth
- 47 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
85 tons of TNT
That is about 1/178 of the Hiroshima bomb. A magnitude 5.0 releases about 6 times more energy.
Tectonic setting
23 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
47 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 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.3 on November 13, 2011. 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 1,400 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 · 153 km W of this epicenter
- 7.8south of the Fiji IslandsDecember 9, 2007 · 284 km NW of this epicenter
- 7.7Kermadec Islands regionOctober 20, 1986 · 28 km NW of this epicenter
- 7.6Kermadec Islands regionJuly 6, 2011 · 149 km S of this epicenter
- 7.5Kermadec Islands regionFebruary 27, 1955 · 51 km E of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 247 km SW of this epicenter
- 7.4Kermadec Islands regionOctober 21, 2011 · 87 km S of this epicenter
- 7.3Kermadec Islands regionSeptember 14, 1959 · 128 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 16 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 · 169 km away
Limited damage (under $1M)tsunami
- 1917M8.0
Kermadec Islands
1 May 1917 · 140 km away
tsunami
- 1955M7.8
Kermadec Islands
27 Feb 1955 · 64 km away
- 1976M7.8
Kermadec Islands
14 Jan 1976 · 218 km away · intensity VIII
- 2007M7.8
Kermadec Islands
9 Dec 2007 · 284 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.