Reviewed by USGS21y ago
M4.1 earthquake in Fiji region
Monday, April 18, 2005, 02:23:53 UTC · 19.613°S, 177.658°W
A magnitude 4.1 earthquake struck in Fiji region on Monday, April 18, 2005, 02:23:53 UTC, at a depth of 421.0 km (deep).
- Magnitude
- 4.1
- Light · mb
- Depth
- 421 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
21 tons of TNT
That is about 1/707 of the Hiroshima bomb. A magnitude 5.0 releases about 22 times more energy.
Tectonic setting
124 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
421 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 2 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.5 on May 11, 2005. 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 1,413 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.0TongaJanuary 4, 1903 · 281 km E of this epicenter
- 7.8159 km W of Pangai, TongaDecember 14, 1950 · 187 km E of this epicenter
- 7.8Fiji regionJanuary 1, 1919 · 55 km NW of this epicenter
- 7.8192 km WSW of Haveluloto, TongaOctober 14, 1997 · 292 km S of this epicenter
- 7.6178 km E of Levuka, FijiFebruary 22, 1909 · 212 km NW of this epicenter
- 7.6240 km E of Levuka, FijiMarch 9, 1994 · 192 km NW of this epicenter
- 7.5262 km WNW of Haveluloto, TongaMay 21, 1962 · 57 km S of this epicenter
- 7.4227 km E of Levuka, FijiAugust 21, 1910 · 221 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 9 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1937M8.1
Fiji Islands
16 Apr 1937 · 221 km away
- 1903M8.0
Tonga Islands
4 Jan 1903 · 281 km away
- 1909M7.8
Fiji Islands
22 Feb 1909 · 228 km away
- 1919M7.8
Fiji Islands
1 Jan 1919 · 55 km away
tsunami
- 1950M7.7
Tonga Islands
14 Dec 1950 · 174 km away · intensity VI
- 1997M7.7
Tonga Islands
14 Oct 1997 · 292 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.