QuakeFactsEvidence report · prepared 2 September 2026https://quakes99.com/entity/iscgem785331
USGS iscgem785331
4 Apr 1971, 19:39
68 km E of Onagawa Chō, Japan
A magnitude 6.1 mw earthquake at 41.9 km depth.
Published location
Where is 68 km E of Onagawa Chō, Japan?
This locator uses the coordinates in the approved source record. It shows geographic context, not a site boundary, safety zone or property-risk area.
38.378000, 142.232000
Open the interactive map ↗Map data © OpenStreetMap contributors
What the numbers mean
Magnitude measures event size; depth locates the source below the surface. Neither value alone establishes local damage or personal risk.
Need a current safety answer?
Use local emergency authorities and the live USGS event page. This historical evidence page is not an alert service.
Continue exploring
Nearby events with a similar magnitude
Catalog fields and provenance
Event ID
iscgem785331
Coordinates
38.378, 142.232
Network
iscgem
Significance
565