QuakeFactsEvidence report · prepared 2 September 2026https://quakes99.com/entity/iscgem610326344
USGS iscgem610326344
23 Apr 1909, 17:39
2 km SW of Alcochete, Portugal
A magnitude 6 mw earthquake at 10 km depth.
Published location
Where is 2 km SW of Alcochete, Portugal?
This locator uses the coordinates in the approved source record. It shows geographic context, not a site boundary, safety zone or property-risk area.
38.739000, -8.978000
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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
iscgem610326344
Coordinates
38.739, -8.978
Network
iscgem
Significance
554