Tonga earthquakes

M4.8 earthquake 55 km SE of Pangai, Tonga

A magnitude 4.8 earthquake struck 55 km SE of Pangai, Tonga on Sat, Dec 21, 1974, 3:29 AM GMT+13 (14:29 UTC), 117 km (73 mi) below the surface.

A larger quake followed: M5.6 100 km SE of Pangai, Tonga. This one was a foreshock.

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

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The earthquake

Magnitude
4.8 (mb), light
Local time
UTC
1974-12-20 14:29:47 UTC
Depth
117.0 km (72.7 mi), intermediate-depth
Epicenter
20.152° S, 173.957° 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
CONSTRAINED_BY_DEPTH_PHASES
Stations used
13

Nearest places

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

Nearby

Within 100 km, magnitude 1.8 and up: 1 in the 60 days after this one and 1 in the 30 days before it.

After

Before

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Sources

From the USGS Earthquake Hazards Program and its partner networks, event usp000096m. Read Tue, Sep 22, 2026, 9:31 PM UTC.