Reviewed by USGS5y ago
M4.3 earthquake south of the Fiji Islands
Saturday, October 2, 2021, 07:14:49 UTC · 21.096°S, 175.332°E
A magnitude 4.3 earthquake struck south of the Fiji Islands on Saturday, October 2, 2021, 07:14:49 UTC, at a depth of 565.9 km (deep).
- Magnitude
- 4.3
- Light · mb
- Depth
- 566 km
- Deep
- 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
53 km
from the nearest mapped plate boundary, between the Australian and Conway Reef plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: deep
566 km
Deep earthquakes (over 300 km) happen deep inside subducting plates. They rarely cause damage, but can be felt faintly over very large distances.
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 248 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.6south of the Fiji IslandsMarch 3, 1990 · 115 km S of this epicenter
- 7.3Vanuatu regionOctober 2, 2021 · 45 km W of this epicenter
- 7.2southeast of the Loyalty IslandsAugust 12, 2016 · 275 km SW of this epicenter
- 7.1Vanuatu regionFebruary 25, 2000 · 235 km NW of this epicenter
- 6.9225 km SW of Nadi, FijiJanuary 3, 2017 · 206 km N of this epicenter
- 6.8south of the Fiji IslandsNovember 7, 1988 · 131 km S of this epicenter
- 6.7Vanuatu regionJune 30, 1993 · 248 km W of this epicenter
- 6.6southeast of the Loyalty IslandsMarch 3, 1990 · 189 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 3 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1990M7.6
Fiji Islands
3 Mar 1990 · 115 km away
- 2016M7.2
Loyalty Islands
12 Aug 2016 · 275 km away · intensity VI
tsunami
- 2017M6.9
Fiji Islands
3 Jan 2017 · 206 km away · intensity VI
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.