Reviewed by USGS8y ago
M4.8 earthquake in Kermadec Islands region
Tuesday, September 11, 2018, 11:12:22 UTC · 31.960°S, 179.416°W
A magnitude 4.8 earthquake struck in Kermadec Islands region on Tuesday, September 11, 2018, 11:12:22 UTC, at a depth of 129.8 km (intermediate). It is the strongest earthquake within 300 km since an M4.8 on September 10, 2018.
- Magnitude
- 4.8
- Light · mb
- Depth
- 130 km
- Intermediate
- 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
239 tons of TNT
That is about 1/63 of the Hiroshima bomb. A magnitude 5.0 releases about 2 times more energy.
Tectonic setting
37 km
from the nearest mapped plate boundary, between the Kermadec and Australian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: intermediate
130 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 4 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.5 on September 24, 2018. 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 1,782 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 · 275 km E of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 279 km NE of this epicenter
- 7.4Kermadec Islands regionMay 16, 2006 · 20 km NE of this epicenter
- 7.3Kermadec Islands, New ZealandMarch 26, 1963 · 275 km NE of this epicenter
- 7.3Kermadec Islands, New ZealandJuly 25, 1968 · 177 km NE of this epicenter
- 7.2Kermadec Islands, New ZealandFebruary 9, 1978 · 242 km NE of this epicenter
- 7.2Kermadec Islands, New ZealandJune 3, 2001 · 266 km N of this epicenter
- 7.2Kermadec Islands, New ZealandAugust 2, 1941 · 298 km NE of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 4 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1968M7.3
S Of, Raoul
25 Jul 1968 · 161 km away
Limited damage (under $1M)tsunami
- 1978M7.7
S Of
9 Feb 1978 · 242 km away
- 2014M6.9
Sse Of Raoul Island
23 Jun 2014 · 273 km away
tsunami
- 2013M6.5
S Of, Raoul
30 Sep 2013 · 155 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.