QuakeFactsEvidence report · prepared 2 September 2026https://quakes99.com/entity/iscgem869543
USGS iscgem869543
15 Mar 1964, 22:30
91 km SSE of Olhão, Portugal
A magnitude 6.6 mw earthquake at 28.5 km depth.
Published location
Where is 91 km SSE of Olhão, 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.
36.219000, -7.639000
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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
iscgem869543
Coordinates
36.219, -7.639
Network
iscgem
Significance
670