Reviewed by USGSTonga34y ago
M6.1 earthquake 217 km WSW of Haveluloto, Tonga
Tuesday, August 4, 1992, 06:58:32 UTC · 21.738°S, 177.214°W
A magnitude 6.1 earthquake struck 217 km WSW of Haveluloto, Tonga on Tuesday, August 4, 1992, 06:58:32 UTC, at a depth of 252.9 km (intermediate). It is the strongest earthquake within 300 km since an M7.2 on July 11, 1992.
- Magnitude
- 6.1
- Strong · mwb
- Depth
- 253 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 earthquake
In context
How big was it, and why here?
Energy released
21 kilotons of TNT
That is about the energy of the Hiroshima bomb. It released about 45 times the energy of a magnitude 5.0.
Tectonic setting
70 km
from the nearest mapped plate boundary, between the Tonga and Australian plates. Earthquakes cluster along boundaries like this one, where plates collide, pull apart or slide past each other.
Depth: intermediate
253 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 100 km
USGS has not published any M2.5+ earthquake within 100 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 1,042 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 7.8159 km W of Pangai, TongaDecember 14, 1950 · 266 km NE of this epicenter
- 7.8Fiji regionJanuary 1, 1919 · 284 km N of this epicenter
- 7.5262 km WNW of Haveluloto, TongaMay 21, 1962 · 185 km N of this epicenter
- 7.4Fiji regionSeptember 28, 1957 · 178 km NW of this epicenter
- 7.3227 km WNW of Haveluloto, TongaApril 16, 1937 · 127 km N of this epicenter
- 7.3Fiji regionMay 25, 1944 · 231 km W of this epicenter
- 7.2Fiji regionOctober 9, 1967 · 213 km W of this epicenter
- 7.2241 km WNW of Houma, TongaAugust 21, 1911 · 193 km N 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, which together caused about 1 recorded deaths. The most severe:
- 1977M7.2
Tonga Trench
22 Jun 1977 · 185 km away · intensity IV
1 death$1 million damagetsunami
- 1937M8.1
Fiji Islands
16 Apr 1937 · 34 km away
- 1903M8.0
Tonga Islands
4 Jan 1903 · 300 km away
- 1919M7.8
Fiji Islands
1 Jan 1919 · 284 km away
tsunami
- 1950M7.7
Tonga Islands
14 Dec 1950 · 279 km away · intensity VI
- 1982M7.7
Tonga Trench
19 Dec 1982 · 300 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.