M3.9 earthquake 74 km W of Pangai, Tonga
A magnitude 3.9 earthquake struck 74 km W of Pangai, Tonga on Fri, Oct 20, 1978, 9:17 PM GMT+13 (08:17 UTC), 194 km (121 mi) below the surface.
A larger quake followed: M4.7 131 km W of Pangai, Tonga. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 3.9 (mb), minor
- Local time
- UTC
- 1978-10-20 08:17:10 UTC
- Depth
- 194.0 km (120.5 mi), intermediate-depth
- Epicenter
- 19.757° S, 175.063° 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.
- Stations used
- 10
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.5 and up: 1 in the 60 days after this one and 1 in the 30 days before it.
After
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0000x2c. Read Wed, Sep 23, 2026, 4:24 AM UTC.