Reviewed by USGSTonga21y ago
M4.2 earthquake 257 km WNW of Haveluloto, Tonga
Wednesday, March 9, 2005, 20:13:08 UTC · 20.556°S, 177.602°W
A magnitude 4.2 earthquake struck 257 km WNW of Haveluloto, Tonga on Wednesday, March 9, 2005, 20:13:08 UTC, at a depth of 500.3 km (deep).
- Magnitude
- 4.2
- Light · mb
- Depth
- 500 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
144 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
500 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 3 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M4.8 on March 19, 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 1,262 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.0TongaJanuary 4, 1903 · 278 km E of this epicenter
- 7.8159 km W of Pangai, TongaDecember 14, 1950 · 204 km NE of this epicenter
- 7.8Fiji regionJanuary 1, 1919 · 146 km N of this epicenter
- 7.8192 km WSW of Haveluloto, TongaOctober 14, 1997 · 192 km SE of this epicenter
- 7.7Fiji regionAugust 19, 2002 · 235 km SW of this epicenter
- 7.6240 km E of Levuka, FijiMarch 9, 1994 · 293 km N of this epicenter
- 7.5262 km WNW of Haveluloto, TongaMay 21, 1962 · 54 km N of this epicenter
- 7.4Fiji regionSeptember 28, 1957 · 78 km W of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 10 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700. The most severe:
- 1937M8.1
Fiji Islands
16 Apr 1937 · 122 km away
- 1903M8.0
Tonga Islands
4 Jan 1903 · 278 km away
- 1919M7.8
Fiji Islands
1 Jan 1919 · 146 km away
tsunami
- 1950M7.7
Tonga Islands
14 Dec 1950 · 204 km away · intensity VI
- 1997M7.7
Tonga Islands
14 Oct 1997 · 192 km away
tsunami
- 2002M7.7
Fiji Islands
19 Aug 2002 · 235 km away
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.