QuakeFactsEvidence report · prepared 2 September 2026https://quakes99.com/entity/iscgem888579
USGS iscgem888579
12 Aug 1956, 17:59
81 km S of Shimoda, Japan
A magnitude 6.4 mw earthquake at 20 km depth.
Published location
Where is 81 km S of Shimoda, 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.
33.941000, 138.913000
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What the numbers mean
Magnitude measures event size; depth locates the source below the surface. Neither value alone establishes local damage or personal risk.
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Use local emergency authorities and the live USGS event page. This historical evidence page is not an alert service.
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Catalog fields and provenance
Event ID
iscgem888579
Coordinates
33.941, 138.913
Network
iscgem
Significance
626