October 10, 1977 Earthquake: Tonga Trench
A magnitude 7.2 earthquake struck Tonga Trench on October 10, 1977 at 11:53:53 UTC, 33 km below the surface. It caused a tsunami.
Map
Where it struck, with the other significant earthquakes within 200 km. Circles are sized and colored by magnitude; select one for its page.
The earthquake
- Date
- October 10, 1977
- Time
- 11:53:53 UTC
- Place
- Tonga Trench
- Magnitude
- 7.2 (Ms)
- Magnitude scales
- Ms 7.2 · mb 6.6
- Focal depth
- 33 km (21 mi)
- Tsunami
- Yes: the tsunami it caused
- Epicenter
- 25.856° S, 175.406° W
- Country
- Tonga
- Region
- Central and South Pacific
- USGS record
- The USGS’s page for this earthquake
Ms: surface-wave magnitude. mb: body-wave (P-wave) magnitude. NCEI’s headline magnitude is the best of these for the earthquake.
The toll
The record gives no deaths, injuries or damage for this earthquake.
Magnitude estimates
The magnitudes the USGS catalog lists for this earthquake, by scale and by who computed them. NCEI’s own scales are in the table above.
| Mag. | Scale | Computed by | Notes |
|---|---|---|---|
| 7.2 | Ms, surface-wave | USGS National Earthquake Information Center | Preferred · Reviewed |
| 7.27 | Mw, moment | ISC-GEM global catalog | Final · ±0.1 |
| 7.3 | Mwc, centroid moment | Global CMT project | Preliminary |
Sources NCEI cites
The publications NCEI lists for this record. The numbers match the “reference #” notes in its account above.
- #1053 National Earthquake Information Center (NEIC) (1971 to 2013). Preliminary Determination of Epicenters (PDE), a weekly and monthly publication, National Earthquake Information Center, U.S. Geological Survey, Golden, Colorado, 1971 to 2013.
Other significant earthquakes nearby
Within 200 km, the deadliest first.
More
Significant earthquakes of 1977The 1900sEvery quake the USGS located in 1977Recent earthquakes near hereThis day in weather history
Sources
Significant earthquakes from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-10-01. NCEI earthquake 6453. The written accounts and the magnitude estimates are from the USGS earthquake catalog, event usp0000qzg, matched to this record by time, place and magnitude.