M4.6 earthquake 105 km N of Naze, Japan

A magnitude 4.6 earthquake struck 105 km N of Naze, Japan on Mon, Mar 16, 1981, 6:33 AM JST (21:33 UTC), 33 km (21 mi) below the surface.

A larger quake followed: M5.4 111 km N of Naze, 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
4.6	mb, body-wave	USGS National Earthquake Information Center	Preferred · Reviewed · 7 stations
5.77	Mw, moment	ISC-GEM global catalog	Final · ±0.2

The USGS’s account of the effects of this earthquake.

FELT (IV JMA) ON AKUSEKISHIMA.

From the USGS event page for usp0001cqp. U.S. Geological Survey text and figures are in the public domain.

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 1.6 and up: 11 in the 60 days after this one and 5 in the 30 days before it.

From the USGS Earthquake Hazards Program and its partner networks, event usp0001cqp (also filed as iscgem629928). Read Fri, Oct 2, 2026, 4:08 PM UTC.