QuakeFactsEvidence report · prepared 2 September 2026https://quakes99.com/entity/iscgem888171
USGS iscgem888171
18 Apr 1956, 11:00
61 km WSW of Adak, Alaska
A magnitude 6.1 mw earthquake at 45 km depth.
Published location
Where is 61 km WSW of Adak, Alaska?
This locator uses the coordinates in the approved source record. It shows geographic context, not a site boundary, safety zone or property-risk area.
51.662000, -177.449000
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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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Catalog fields and provenance
Event ID
iscgem888171
Coordinates
51.662, -177.449
Network
iscgem
Significance
565