Reviewed by USGSTonga7y ago
M4.7 earthquake 296 km WNW of Haveluloto, Tonga
Monday, December 31, 2018, 13:15:17 UTC · 20.514°S, 177.982°W
A magnitude 4.7 earthquake struck 296 km WNW of Haveluloto, Tonga on Monday, December 31, 2018, 13:15:17 UTC, at a depth of 525.0 km (deep). It is the strongest earthquake within 300 km since an M4.8 on December 30, 2018.
- Magnitude
- 4.7
- Light · mb
- Depth
- 525 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
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
184 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
525 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 9 M2.5+ earthquakes within 50 km in the following 30 days; the largest was M5.8 on January 27, 2019. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.7289 km W of Haveluloto, Tonga7y ago · 46 km S of this epicenter
- 5.8295 km WNW of Haveluloto, Tonga7y ago · 49 km N of this epicenter
- 4.5298 km WNW of Haveluloto, Tonga7y ago · 16 km N of this epicenter
- 4.3265 km WNW of Haveluloto, Tonga7y ago · 40 km E of this epicenter
- 4.2263 km WNW of Haveluloto, Tonga7y ago · 45 km NE of this epicenter
- 4.2Fiji region7y ago · 21 km N of this epicenter
- 4.7282 km WNW of Haveluloto, Tonga7y ago · 34 km NE of this epicenter
- 4.7268 km W of Haveluloto, Tonga7y ago · 38 km SE of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 1,730 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.22018 Fiji EarthquakeAugust 19, 2018 · 268 km N of this epicenter
- 7.8159 km W of Pangai, TongaDecember 14, 1950 · 238 km E of this epicenter
- 7.8Fiji regionJanuary 1, 1919 · 133 km N of this epicenter
- 7.8192 km WSW of Haveluloto, TongaOctober 14, 1997 · 216 km SE of this epicenter
- 7.7Fiji regionAugust 19, 2002 · 206 km SW of this epicenter
- 7.6178 km E of Levuka, FijiFebruary 22, 1909 · 279 km NW of this epicenter
- 7.6240 km E of Levuka, FijiMarch 9, 1994 · 279 km N of this epicenter
- 7.5262 km WNW of Haveluloto, TongaMay 21, 1962 · 72 km NE 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:
- 2018M8.2
Fiji Islands
19 Aug 2018 · 268 km away · intensity V
tsunami
- 1937M8.1
Fiji Islands
16 Apr 1937 · 150 km away
- 1909M7.8
Fiji Islands
22 Feb 1909 · 299 km away
- 1919M7.8
Fiji Islands
1 Jan 1919 · 133 km away
tsunami
- 1950M7.7
Tonga Islands
14 Dec 1950 · 236 km away · intensity VI
- 1997M7.7
Tonga Islands
14 Oct 1997 · 216 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.