QuakeFactsEvidence report · prepared 2 September 2026https://quakes99.com/entity/nc73594531
USGS nc73594531
18 Jul 2021, 07:46
12km W of Petrolia, CA
A magnitude 5.1 mw earthquake at 30.9 km depth.
Published location
Where is 12km W of Petrolia, CA?
This locator uses the coordinates in the approved source record. It shows geographic context, not a site boundary, safety zone or property-risk area.
40.323500, -124.425500
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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
nc73594531
Coordinates
40.3235, -124.4255
Network
nc
Significance
719