QuakeFactsEvidence report · prepared 2 September 2026https://quakes99.com/entity/iscgemsup912676
USGS iscgemsup912676
4 Dec 1920, 05:51
off the coast of South Africa
A magnitude 6.4 mw earthquake at 10 km depth.
Published location
Where is off the coast of South Africa?
This locator uses the coordinates in the approved source record. It shows geographic context, not a site boundary, safety zone or property-risk area.
-38.853000, 23.070000
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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
iscgemsup912676
Coordinates
-38.853, 23.07
Network
iscgemsup
Significance
620