M4.9 earthquake 131 km ENE of ‘Ohonua, Tonga
A magnitude 4.9 earthquake struck 131 km ENE of ‘Ohonua, Tonga on Sun, Dec 20, 1987, 3:05 PM GMT+13 (02:05 UTC), 33 km (21 mi) below the surface.
A larger quake followed: M5.5 64 km ENE of ‘Ohonua, Tonga. This one was a foreshock.
Map
Where this earthquake was located, with the others nearby. Select one for its page.
The earthquake
- Magnitude
- 4.9 (mb), light
- Local time
- UTC
- 1987-12-20 02:05:20 UTC
- Depth
- 33.0 km (20.5 mi), shallow
- Epicenter
- 20.929° S, 173.758° 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
Nearest places
Distance and direction from each place to the epicenter, with its forecast.
Nearby
Within 100 km, magnitude 1.9 and up: 2 in the 60 days after this one and 1 in the 30 days before it.
After
- 4.550 km SSE of Pangai, Tonga · 14160 days ago · 33 km deep · 88 km away
- 5.564 km ENE of ‘Ohonua, Tonga · 14119 days ago · 33 km deep · 68 km away
Before
Earthquakes todayTonga earthquakesLive radar here
Sources
From the USGS Earthquake Hazards Program and its partner networks, event usp0003be1. Read Mon, Sep 28, 2026, 1:29 PM UTC.