Reviewed by USGS8y ago
M4.3 earthquake south of the Kermadec Islands
Sunday, September 16, 2018, 01:49:50 UTC · 32.242°S, 179.166°W
A magnitude 4.3 earthquake struck south of the Kermadec Islands on Sunday, September 16, 2018, 01:49:50 UTC, at a depth of 90.9 km (intermediate).
- Magnitude
- 4.3
- Light · mb
- Depth
- 91 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
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
70 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
91 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 2 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 1,764 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 · 265 km NE of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 295 km NE of this epicenter
- 7.4Kermadec Islands regionMay 16, 2006 · 50 km N of this epicenter
- 7.3Kermadec Islands, New ZealandMarch 26, 1963 · 288 km NE of this epicenter
- 7.3Kermadec Islands, New ZealandJuly 25, 1968 · 187 km NE of this epicenter
- 7.2Kermadec Islands, New ZealandFebruary 9, 1978 · 244 km NE of this epicenter
- 7.2Kermadec Islands, New ZealandJune 3, 2001 · 291 km N of this epicenter
- 7.2Kermadec Islands, New ZealandApril 17, 1919 · 216 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 · 176 km away
Limited damage (under $1M)tsunami
- 1978M7.7
S Of
9 Feb 1978 · 244 km away
- 2014M6.9
Sse Of Raoul Island
23 Jun 2014 · 287 km away
tsunami
- 2013M6.5
S Of, Raoul
30 Sep 2013 · 167 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.