Reviewed by USGSNew Zealand5y ago
M4.3 earthquake in Kermadec Islands, New Zealand
Thursday, May 13, 2021, 08:51:13 UTC · 29.573°S, 177.576°W
A magnitude 4.3 earthquake struck in Kermadec Islands, New Zealand on Thursday, May 13, 2021, 08:51:13 UTC, at a depth of 81.9 km (intermediate).
- Magnitude
- 4.3
- Light · mb
- Depth
- 82 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
123 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: intermediate
82 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 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.8 on May 14, 2021. 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 2,360 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 · 201 km SE of this epicenter
- 8.12021 Kermadec Islands, New Zealand EarthquakeMarch 4, 2021 · 33 km SE of this epicenter
- 8.01976 Kermadec Islands, New Zealand EarthquakeJanuary 14, 1976 · 128 km N of this epicenter
- 7.7Kermadec Islands regionOctober 20, 1986 · 200 km NE of this epicenter
- 7.6Kermadec Islands regionJuly 6, 2011 · 120 km E of this epicenter
- 7.5Kermadec Islands regionFebruary 27, 1955 · 236 km NE of this epicenter
- 7.5Kermadec Islands, New ZealandNovember 16, 1917 · 40 km SW of this epicenter
- 7.4Kermadec Islands, New ZealandMarch 4, 2021 · 28 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 19 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1986M8.1
Raoul
20 Oct 1986 · 200 km away
Limited damage (under $1M)tsunami
- 1976M7.9
Kermadec Islands
14 Jan 1976 · 45 km away
Limited damage (under $1M)tsunami
- 1968M7.3
S Of, Raoul
25 Jul 1968 · 158 km away
Limited damage (under $1M)tsunami
- 2021M8.1
Sse Of Raoul Island
4 Mar 2021 · 35 km away · intensity IX
tsunami
- 1917M8.0
Kermadec Islands
1 May 1917 · 70 km away
tsunami
- 1955M7.8
Kermadec Islands
27 Feb 1955 · 267 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.