Reviewed by USGSTonga29y ago
M7.8 earthquake 192 km WSW of Haveluloto, Tonga
Tuesday, October 14, 1997, 09:53:18 UTC · 22.101°S, 176.772°W
A magnitude 7.8 earthquake struck 192 km WSW of Haveluloto, Tonga on Tuesday, October 14, 1997, 09:53:18 UTC, at a depth of 167.3 km (intermediate). It is the strongest earthquake within 300 km since an M7.8 on December 14, 1950.
- Magnitude
- 7.8
- Major · mwb
- Depth
- 167 km
- Intermediate
- Felt reports
- 0
- Did You Feel It?
- Est. shaking
- VII
- Very strong (ShakeMap)
- PAGER alert
- None
- Not issued
- Tsunami
- No flag
- USGS feed
Outlined circle: this earthquakeDashed circle: 200 km aftershock search areaColoured lines: estimated shaking intensity (USGS ShakeMap)
In context
How big was it, and why here?
Energy released
7.6 megatons of TNT
That is about 502 times the Hiroshima bomb. It released about 15,849 times the energy of a magnitude 5.0.
Tectonic setting
16 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
167 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 200 km
USGS lists 38 M2.5+ earthquakes within 200 km in the following 30 days; the largest was M5.8 on October 19, 1997. Most nearby activity right after a large earthquake is aftershocks, which usually become less frequent over days and weeks.
- 4.8137 km SW of Haveluloto, Tonga29y ago · 55 km NE of this epicenter
- 4.9188 km WSW of Haveluloto, Tonga29y ago · 22 km N of this epicenter
- 4.2154 km WSW of Haveluloto, Tonga29y ago · 61 km N of this epicenter
- 4.0171 km W of Haveluloto, Tonga29y ago · 138 km N of this epicenter
- 4.7223 km W of Haveluloto, Tonga29y ago · 124 km NW of this epicenter
- 4.5165 km WSW of Haveluloto, Tonga29y ago · 42 km N of this epicenter
- 4.0172 km WSW of Haveluloto, Tonga29y ago · 42 km N of this epicenter
- 4.7158 km WSW of Haveluloto, Tonga29y ago · 63 km N of this epicenter
Regional history
Past M5+ earthquakes within 300 km
USGS lists 1,381 M5.0+ earthquakes within 300 km before this one (catalog from 1900; older records are less complete). The strongest:
- 8.0TongaJanuary 4, 1903 · 297 km NE of this epicenter
- 7.8159 km W of Pangai, TongaDecember 14, 1950 · 282 km N of this epicenter
- 7.6south of the Fiji IslandsDecember 18, 1963 · 295 km S of this epicenter
- 7.5262 km WNW of Haveluloto, TongaMay 21, 1962 · 235 km N of this epicenter
- 7.4Fiji regionSeptember 28, 1957 · 238 km NW of this epicenter
- 7.4Fiji regionAugust 5, 1996 · 224 km NW of this epicenter
- 7.3227 km WNW of Haveluloto, TongaApril 16, 1937 · 177 km N of this epicenter
- 7.3Fiji regionMay 25, 1944 · 281 km W 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 · 124 km away · intensity IV
1 death$1 million damagetsunami
- 1937M8.1
Fiji Islands
16 Apr 1937 · 71 km away
- 1903M8.0
Tonga Islands
4 Jan 1903 · 297 km away
- 1950M7.7
Tonga Islands
14 Dec 1950 · 300 km away · intensity VI
- 1982M7.7
Tonga Trench
19 Dec 1982 · 244 km away
tsunami
- 1997M7.7
Tonga Islands
14 Oct 1997 · 0 km away
tsunami
NOAA NCEI Global Significant Earthquake Database. Historical figures are estimates; older records are incomplete.