QuakeFactsEvidence report · prepared 2 September 2026https://quakes99.com/entity/iscgem889402
USGS iscgem889402
6 Apr 1955, 19:48
Broken Ridge
A magnitude 6.1 mw earthquake at 15 km depth.
Published location
Where is Broken Ridge?
This locator uses the coordinates in the approved source record. It shows geographic context, not a site boundary, safety zone or property-risk area.
-33.771000, 86.913000
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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.
Need a current safety answer?
Use local emergency authorities and the live USGS event page. This historical evidence page is not an alert service.
Catalog fields and provenance
Event ID
iscgem889402
Coordinates
-33.771, 86.913
Network
iscgem
Significance
563