Tonga earthquakes

M6.8 earthquake Tonga region

A magnitude 6.8 earthquake struck in the Tonga region on Thu, Jun 23, 1977, 1:08 AM GMT+13 (12:08 UTC), 65 km (40 mi) below the surface.

Nuku‘alofa forecast More in Tonga

Map

Where this earthquake was located, with the others nearby. Select one for its page.

Open the live map with earthquakes

The earthquake

Magnitude: 6.8 (mb), strong
Local time: Thu, Jun 23, 1977, 1:08 AM GMT+13
UTC: 1977-06-22 12:08:33 UTC
Depth: 65.0 km (40.4 mi), shallow
Epicenter: 22.878° S, 175.900° W
Region: Tonga
Strongest shaking: IV, light shaking
Tsunami flag: No
Status: Reviewed by a seismologist

Shaking

The USGS ShakeMap: shaking estimated from seismic stations and the quake’s size, on the Modified Mercalli intensity scale.

Strongest estimated: IV, light shaking
Peak ground acceleration: 2.3% of gravity
Peak ground velocity: 0.6 cm/s
Map: Automatic

USGS ShakeMap: estimated shaking intensity around the epicenter — Estimated shaking intensity. Map: USGS ShakeMap.

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Stations used: 331

Nearest places

Distance and direction from each place to the epicenter, with its forecast.

Nuku‘alofa, TongaPopulation 22,400. Forecast207 kmSSW

Nearby

Within 100 km, magnitude 2.5 and up: 24 in the 60 days after this one and 1 in the 30 days before it.

After

Before

4.7231 km SW of ‘Ohonua, TongaMon, Jun 13, 8:13 AM GMT+13 · 17998 days ago · 123 km deep · 39 km away

Earthquakes today Tonga earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event usp0000pdx (also filed as gcmtg062277a, gcmt19770622120833, iscgem697569, atlas19770622120834). Read Tue, Sep 22, 2026, 3:08 AM UTC.