Tonga earthquakes

M5.5 earthquake 93 km E of Hihifo, Tonga

A magnitude 5.5 earthquake struck 93 km E of Hihifo, Tonga on Fri, Sep 30, 1977, 10:22 AM GMT-11 (21:22 UTC), 33 km (21 mi) below the surface.

A larger quake followed: M5.9 84 km ENE of Hihifo, Tonga. This one was a foreshock.

Apia forecast More in Tonga

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The earthquake

Magnitude: 5.5 (ms), moderate
Local time: Fri, Sep 30, 1977, 10:22 AM GMT-11
UTC: 1977-09-30 21:22:57 UTC
Depth: 33.0 km (20.5 mi), shallow
Epicenter: 16.041° S, 172.925° W
Region: Tonga
Tsunami flag: No
Status: Reviewed by a seismologist

Did you feel it?

No one has reported feeling this quake to the USGS.

How well it is located

Reviewed by a seismologist.

Depth from: OPERATOR_ASSIGNED
Stations used: 119

Nearest places

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

Apia, SamoaPopulation 40,407. Forecast275 kmSSW

Nearby

Within 100 km, magnitude 2.5 and up: 3 in the 60 days after this one and 9 in the 30 days before it.

After

Before

Earthquakes today Tonga earthquakes Live radar here

Sources

From the USGS Earthquake Hazards Program and its partner networks, event usp0000qv4 (also filed as gcmtb093077b, gcmt19770930212257, iscgem693974). Read Tue, Sep 22, 2026, 11:03 AM UTC.