Reviewed by USGS19y ago
M4.2 earthquake south of the Fiji Islands
Friday, December 28, 2007, 06:47:39 UTC · 25.192°S, 177.414°W
A magnitude 4.2 earthquake struck south of the Fiji Islands on Friday, December 28, 2007, 06:47:39 UTC, at a depth of 113.1 km (intermediate).
- Magnitude
- 4.2
- Light · mb
- Depth
- 113 km
- Intermediate
- 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
24 km
from the nearest mapped plate boundary, between the Kermadec and Australian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: intermediate
113 km
Intermediate-depth earthquakes usually break inside a plate that is sinking into the mantle. Shaking spreads over a wide area but is gentler at the epicenter than a shallow quake of the same size.
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 M3.7 on January 19, 2008. 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 1,061 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8south of TongaOctober 11, 1975 · 234 km E of this epicenter
- 7.8south of the Fiji IslandsDecember 9, 2007 · 90 km S of this epicenter
- 7.6south of the Fiji IslandsDecember 18, 1963 · 76 km NE of this epicenter
- 7.3south of the Fiji IslandsJanuary 20, 1970 · 82 km S of this epicenter
- 7.3south of the Fiji IslandsMarch 30, 1972 · 300 km W of this epicenter
- 7.2south of the Fiji IslandsNovember 24, 1960 · 131 km NE of this epicenter
- 7.2south of TongaOctober 10, 1977 · 215 km E of this epicenter
- 7.2south of the Fiji IslandsApril 16, 1996 · 131 km N of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 7 damaging, deadly or tsunami-generating earthquakes within 300 km of this epicenter since 1700, which together caused about 1 recorded deaths. The most severe:
- 1977M7.2
Tonga Trench
22 Jun 1977 · 300 km away · intensity IV
1 death$1 million damagetsunami
- 1975M7.8
S Of Tonga
11 Oct 1975 · 234 km away
- 2007M7.8
Kermadec Islands
9 Dec 2007 · 90 km away
tsunami
- 1982M7.7
Tonga Trench
19 Dec 1982 · 196 km away
tsunami
- 1963M7.5
Tonga Trench
18 Dec 1963 · 93 km away
tsunami
- 1977M7.2
Tonga Trench
10 Oct 1977 · 215 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.