Reviewed by USGSTonga29y ago
M4.0 earthquake 171 km W of Haveluloto, Tonga
Sunday, November 2, 1997, 15:41:15 UTC · 20.861°S, 176.829°W
A magnitude 4.0 earthquake struck 171 km W of Haveluloto, Tonga on Sunday, November 2, 1997, 15:41:15 UTC, at a depth of 200.0 km (intermediate).
- Magnitude
- 4.0
- Light · mb
- Depth
- 200 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
15 tons of TNT
That is about 1/998 of the Hiroshima bomb. A magnitude 5.0 releases about 32 times more energy.
Tectonic setting
58 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
200 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 has not published any M2.5+ earthquake within 50 km in the 30 days after this event.
Regional history
Past M5+ earthquakes within 300 km
USGS lists 1,203 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.0TongaJanuary 4, 1903 · 213 km NE of this epicenter
- 7.8159 km W of Pangai, TongaDecember 14, 1950 · 163 km NE of this epicenter
- 7.8Fiji regionJanuary 1, 1919 · 216 km NW of this epicenter
- 7.8192 km WSW of Haveluloto, TongaOctober 14, 1997 · 138 km S of this epicenter
- 7.5262 km WNW of Haveluloto, TongaMay 21, 1962 · 108 km NW of this epicenter
- 7.4Fiji regionSeptember 28, 1957 · 162 km W of this epicenter
- 7.4Fiji regionAugust 5, 1996 · 155 km W of this epicenter
- 7.3227 km WNW of Haveluloto, TongaApril 16, 1937 · 59 km NW of this epicenter
History · NOAA
Deadliest earthquakes in this area
NOAA’s significant-earthquake database lists 11 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 · 244 km away · intensity IV
1 death$1 million damagetsunami
- 1937M8.1
Fiji Islands
16 Apr 1937 · 73 km away
- 1903M8.0
Tonga Islands
4 Jan 1903 · 213 km away
- 1948M7.9
Tonga Islands
8 Sep 1948 · 294 km away
tsunami
- 1919M7.8
Fiji Islands
1 Jan 1919 · 216 km away
tsunami
- 1950M7.7
Tonga Islands
14 Dec 1950 · 174 km away · intensity VI
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.