Reviewed by USGS15y ago
M4.7 earthquake in Fiji region
Sunday, September 25, 2011, 02:03:01 UTC · 21.674°S, 179.283°W
A magnitude 4.7 earthquake struck in Fiji region on Sunday, September 25, 2011, 02:03:01 UTC, at a depth of 592.8 km (deep). It is the strongest earthquake within 300 km since an M4.7 on September 20, 2011.
- Magnitude
- 4.7
- Light · mb
- Depth
- 593 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
169 tons of TNT
That is about 1/89 of the Hiroshima bomb. A magnitude 5.0 releases about 3 times more energy.
Tectonic setting
277 km
from the nearest mapped plate boundary, between the Tonga and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: deep
593 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 1,295 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8Fiji regionJanuary 1, 1919 · 290 km NE of this epicenter
- 7.8192 km WSW of Haveluloto, TongaOctober 14, 1997 · 263 km E of this epicenter
- 7.7Fiji regionAugust 19, 2002 · 24 km W of this epicenter
- 7.5262 km WNW of Haveluloto, TongaMay 21, 1962 · 259 km NE of this epicenter
- 7.4Fiji regionSeptember 28, 1957 · 159 km NE of this epicenter
- 7.4Fiji regionAugust 5, 1996 · 149 km NE of this epicenter
- 7.3227 km WNW of Haveluloto, TongaApril 16, 1937 · 237 km NE of this epicenter
- 7.3Fiji regionMay 25, 1944 · 19 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 5 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1937M8.1
Fiji Islands
16 Apr 1937 · 237 km away
- 1919M7.8
Fiji Islands
1 Jan 1919 · 290 km away
tsunami
- 1997M7.7
Tonga Islands
14 Oct 1997 · 263 km away
tsunami
- 2002M7.7
Fiji Islands
19 Aug 2002 · 24 km away
- 1957M7.5
Fiji Islands
28 Sep 1957 · 163 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.