Quake information: Reported (unconfirmed) earthquake: 0.5 mi southwest of San Francisco, California, USA, 27 April 2021 07:56 GMT

It is assumed that this record was not from an actual earthquake. This may be due to some other (unknown) event that causes tremors, e.g. B. Explosions, sonic booms, weather or other human or natural causes. Even officially reported earthquakes are sometimes removed again later when seismic signals that were initially processed automatically are later manually reinterpreted so that they do not originate from real earthquakes.
This can happen when initial automatic calculations return an earthquake, but turn out to be incorrect in subsequent (manual) revision.
The first report is below:
Our surveillance service AllQuakes received reports of an earthquake in or near San Francisco, California, USA at around 7:56 GMT. Unless at least one national or international seismological agency confirms this, their status remains unconfirmed.
27 Apr 08:04 UTC: First report: VolcanoDiscovery after 8 minutes.
[show map]
[smaller] [bigger]
If you felt this quake (or if you were near the epicenter) please share your experience with us and submit a short “I Felt It” report! Other users would love to hear about it!
Even if you did NOT feel the quake even though you were in the area, please Report it! Your contribution is also useful for earthquake research and for earthquake hazard analysis and mitigation. You can use your device’s location or the map to tell you where you were during the earthquake. Many Thanks!
Data for the same earthquake reported by different authorities
Info: The more agencies report on the same quake and publish similar data, the more confidence you can have in the data. It usually takes up to a few hours for the earthquake parameters to be calculated with near optimal accuracy.
size | depth | place | source |
User reports for this quake (2)
Contribute:
Leave a comment if you find a particular report interesting or want to add to it.
Report as inappropriate.
Mark as helpful or interesting.
Submit your own user report!
Visalia, ca / weak shaking (MMI III) / complex movement difficult to describe / very brief : Slight jerk. Almost like I’m dizzy. But the brand new detergent tub fell off the counter and burst all over the floor.
San Francisco 94109 (0 km northeast of the epicenter) [Map] / Very weak shaking (MMI II) / rattling, vibrating / very briefly : One of those times you can’t tell if it’s a quake – but dogs barked
Try our free app!
Previous earthquakes in the same area
Please wait as we search millions of records.
This can take up to 20-30 seconds.
Click here to search our database for previous earthquakes in the same region since 1900!