USGS · August 28, 2026

Magnitude 4.7 earthquake — 85 km W of Petrolia, CA

A magnitude 4.7 earthquake was recorded near 85 km W of Petrolia, CA on Aug 28, 2026, 07:41 PM (local time at the epicentre — PDT, UTC-7), at a depth of about 10.0 km, according to USGS.

USGSFelt by 252 people · community intensity IV (light)Shaking IIIPAGER GreenTsunami flaggedShallow (0–70 km)Reviewed by a seismologist

Updated 2026-09-04 18:15 UTC

The full record

Magnitude
M 4.7 · moment magnitude
Location
85 km W of Petrolia, CA
Local time at the epicentre
Aug 28, 2026, 07:41 PM — PDT, UTC-7
Time (UTC)
2026-08-29 02:41 UTC
Depth
10.0 km · Shallow (0–70 km)
Coordinates
40.450, -125.272
Felt reports
Felt by 252 people · community intensity IV (light)
Estimated shaking
III · Weak
PAGER impact alert
Green — No casualties or significant damage expected.
Tsunami
Flagged for tsunami evaluation by the responsible warning centre.
Significance
436 / 1000 · notable event
Solution quality
149 seismic stations used · 239° azimuthal gap (less well-constrained epicentre)
Review status
Reviewed by a seismologist
Catalog
USGS

Open the official catalog record

Epicentre and nearby recent earthquakes

The highlighted circle is this earthquake. Smaller circles are other events recorded nearby in the last 30 days.

What the shaking was like

Shallow earthquakes release their energy close to the surface, so they are felt more strongly nearby than a deeper earthquake of the same magnitude.

Estimated instrumental shaking III (Weak): Felt indoors; hanging objects swing, like a passing truck.

People who reported it described intensity IV (Light): Felt indoors by many; dishes and windows rattle and parked cars rock.

Felt it yourself? USGS collects first-hand reports through “Did You Feel It?”, and those reports are what produce the community intensity above.

Who lives nearby

About 0 people live in towns within 30 km of the epicentre, and 27,048 within 100 km. Distances are from the epicentre to the town centre.

PlaceDistancePopulation
Ferndale86.4 km E1,369
Fortuna95.7 km E12,000
Humboldt Hill96.4 km ENE3,414
Bayview98.6 km ENE2,510
Rio Dell98.8 km E3,387
Pine Hills99.7 km ENE3,131
Hydesville99.9 km E1,237

Earthquake history in this area

12 earthquakes of magnitude 4.5+ have been recorded within 200 km of this epicentre since 1960.

Other earthquakes near this epicentre

2 other events within 100 km in the last 30 days.

Be first to know about the next earthquake near 85 km W of Petrolia, CA

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Frequently asked questions

How strong was the 85 km W of Petrolia, CA earthquake?

Magnitude 4.7 (moment magnitude), at a depth of 10.0 km. Shallow earthquakes release their energy close to the surface, so they are felt more strongly nearby than a deeper earthquake of the same magnitude.

Exactly when did it happen?

Aug 28, 2026, 07:41 PM (local time at the epicentre — PDT, UTC-7). In universal time: 2026-08-29 02:41 UTC.

Was it felt?

Felt by 252 people · community intensity IV (light). Felt indoors; hanging objects swing, like a passing truck.

Was there a tsunami warning?

Flagged for tsunami evaluation by the responsible warning centre.

Which towns are closest to the epicentre?

The closest is Ferndale, 86.4 km E (population 1,369).

Are earthquakes normal in this area?

Yes. The largest earthquake recorded within 200 km since 1960 was magnitude 7.2 (The 1992 Petrolia, California Earthquake, 1992), and 2 further events were recorded within 100 km in the last 30 days.

How do I get alerts for the next earthquake here?

Install the free SeismoWatch Android app, draw a box over this area, set a minimum magnitude, and turn alerts on.

About this page

Event data: U.S. Geological Survey (USGS), the European-Mediterranean Seismological Centre (EMSC) and, in Venezuela, FUNVISIS. Populated places and time zones: GeoNames (CC BY 4.0). Preliminary solutions are revised as more observations arrive.