Reviewed by USGS5y ago
M4.3 earthquake southeast of the Loyalty Islands
Tuesday, October 5, 2021, 16:57:02 UTC · 22.195°S, 174.059°E
A magnitude 4.3 earthquake struck southeast of the Loyalty Islands on Tuesday, October 5, 2021, 16:57:02 UTC, at a depth of 10.0 km (shallow).
- Magnitude
- 4.3
- Light · mb
- Depth
- 10 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 earthquake
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
0 km
from the nearest mapped plate boundary, between the Conway Reef and New Hebrides plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: shallow
10 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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 482 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.7southeast of the Loyalty IslandsFebruary 10, 2021 · 264 km W of this epicenter
- 7.6south of the Fiji IslandsMarch 3, 1990 · 114 km E of this epicenter
- 7.3Vanuatu regionOctober 2, 2021 · 147 km NE of this epicenter
- 7.2southeast of the Loyalty IslandsNovember 14, 1906 · 254 km W of this epicenter
- 7.2southeast of the Loyalty IslandsAugust 12, 2016 · 102 km W of this epicenter
- 7.1southeast of the Loyalty IslandsAugust 17, 1935 · 267 km W of this epicenter
- 7.1southeast of the Loyalty IslandsApril 14, 1906 · 282 km W of this epicenter
- 7.1Vanuatu regionFebruary 25, 2000 · 298 km N 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:
- 2021M7.7
Loyalty Islands
10 Feb 2021 · 270 km away · intensity VII
tsunami
- 1990M7.6
Fiji Islands
3 Mar 1990 · 114 km away
- 1944M7.5
Loyalty Islands
5 Oct 1944 · 214 km away
- 2016M7.2
Loyalty Islands
12 Aug 2016 · 102 km away · intensity VI
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.