M4.8 earthquake 117 km SSE of Shimoda, Japan

A magnitude 4.8 earthquake struck 117 km SSE of Shimoda, Japan on Wed, Dec 29, 1982, 3:00 AM JST (18:00 UTC), 33 km (21 mi) below the surface.

A larger quake followed: M5.5 107 km SSE of Shimoda, Japan. This one was a foreshock.

Map

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

Different scales measure different things and differ by a few tenths. The USGS marks one as preferred, and it is the one this page uses.

Mag.	Scale	Computed by	Notes
4.8	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · 9 stations
5.16	Mw, moment	ISC-GEM global catalog	Final · ±0.31

No one has reported feeling this quake to the USGS.

Reviewed by a seismologist.

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

Within 100 km, magnitude 1.8 and up: 10 in the 60 days after this one and 13 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event usp0001rua (also filed as iscgem587913). Read Fri, Oct 2, 2026, 7:18 PM UTC.