Reviewed by USGSNew Zealand7y ago
M4.2 earthquake in Kermadec Islands, New Zealand
Wednesday, September 18, 2019, 10:06:08 UTC · 30.580°S, 178.166°W
A magnitude 4.2 earthquake struck in Kermadec Islands, New Zealand on Wednesday, September 18, 2019, 10:06:08 UTC, at a depth of 35.0 km (shallow).
- Magnitude
- 4.2
- 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 earthquakeDashed circle: 50 km aftershock search area
In context
How big was it, and why here?
Energy released
30 tons of TNT
That is about 1/500 of the Hiroshima bomb. A magnitude 5.0 releases about 16 times more energy.
Tectonic setting
105 km
from the nearest mapped plate boundary, between the Kermadec and Australian 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 lists 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.0 on October 13, 2019. 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 2,240 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 · 160 km SE of this epicenter
- 8.01976 Kermadec Islands, New Zealand EarthquakeJanuary 14, 1976 · 244 km N of this epicenter
- 7.6Kermadec Islands regionJuly 6, 2011 · 210 km NE of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 87 km N of this epicenter
- 7.4Kermadec Islands regionOctober 21, 2011 · 256 km NE of this epicenter
- 7.4Kermadec Islands regionMay 16, 2006 · 175 km SW of this epicenter
- 7.3Kermadec Islands regionSeptember 14, 1959 · 214 km NE of this epicenter
- 7.3Kermadec Islands, New ZealandMarch 26, 1963 · 81 km NE 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:
- 1976M7.9
Kermadec Islands
14 Jan 1976 · 170 km away
Limited damage (under $1M)tsunami
- 1968M7.3
S Of, Raoul
25 Jul 1968 · 33 km away
Limited damage (under $1M)tsunami
- 1917M8.0
Kermadec Islands
1 May 1917 · 190 km away
tsunami
- 1976M7.8
Kermadec Islands
14 Jan 1976 · 116 km away · intensity VIII
- 1959M7.7
Kermadec Islands
14 Sep 1959 · 257 km away
- 1978M7.7
S Of
9 Feb 1978 · 78 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.