Reviewed by USGS22y ago
M4.2 earthquake in Fiji region
Wednesday, September 15, 2004, 20:36:51 UTC · 19.198°S, 177.713°W
A magnitude 4.2 earthquake struck in Fiji region on Wednesday, September 15, 2004, 20:36:51 UTC, at a depth of 600.0 km (deep).
- Magnitude
- 4.2
- Light · mb
- Depth
- 600 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 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
122 km
from the nearest mapped plate boundary, between the Niuafo'ou and Australian plates. Earthquakes this far from a boundary happen on faults inside a plate, often less frequently but sometimes strongly.
Depth: deep
600 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 lists 1 M2.5+ earthquake within 50 km in the following 30 days; the largest was M4.5 on September 19, 2004. 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 1,358 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.0TongaJanuary 4, 1903 · 298 km E of this epicenter
- 7.8159 km W of Pangai, TongaDecember 14, 1950 · 201 km E of this epicenter
- 7.8Fiji regionJanuary 1, 1919 · 41 km W of this epicenter
- 7.6178 km E of Levuka, FijiFebruary 22, 1909 · 176 km NW of this epicenter
- 7.6240 km E of Levuka, FijiMarch 9, 1994 · 148 km NW of this epicenter
- 7.5262 km WNW of Haveluloto, TongaMay 21, 1962 · 102 km S of this epicenter
- 7.4227 km E of Levuka, FijiAugust 21, 1910 · 177 km NW of this epicenter
- 7.4Fiji regionSeptember 28, 1957 · 163 km SW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 8 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1932M6.4
Koro,Mudu,Suvasavu
8 Mar 1932 · 289 km away · intensity VII
Moderate damage ($1–5M)
- 1937M8.1
Fiji Islands
16 Apr 1937 · 267 km away
- 1903M8.0
Tonga Islands
4 Jan 1903 · 298 km away
- 1909M7.8
Fiji Islands
22 Feb 1909 · 190 km away
- 1919M7.8
Fiji Islands
1 Jan 1919 · 41 km away
tsunami
- 1950M7.7
Tonga Islands
14 Dec 1950 · 183 km away · intensity VI
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.