QuakeFactsEvidence report · prepared 2 September 2026https://quakes99.com/entity/iscgem889544
USGS iscgem889544
21 May 1955, 04:30
Bonin Islands, Japan region
A magnitude 6 mw earthquake at 15 km depth.
Published location
Where is Bonin Islands, Japan region?
This locator uses the coordinates in the approved source record. It shows geographic context, not a site boundary, safety zone or property-risk area.
28.186000, 140.958000
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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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Nearby events with a similar magnitude
Catalog fields and provenance
Event ID
iscgem889544
Coordinates
28.186, 140.958
Network
iscgem
Significance
556