quarry blast · reviewed by a seismologist
M 1.5md
Earthquake near Cotati, CA
No earthquake was likely felt in Cotati in the 24 hours to 8:36 am PST (16:36 UTC). The last one was M 2.4, 8 km (5 mi) S, at 3:02 pm PDT on 2 October 2026, estimated intensity III (weak) in town; 1 felt report to USGS. Every earthquake near Cotati
No: USGS classifies this as a quarry blast, not an earthquake. A magnitude 1.5 quarry blast was recorded 8 km (5 mi) west-southwest of Cotati, CA, at 1:00 pm PDT on 23 June 2026 (20:00 UTC), less than 1 km deep.
USGS: 8 km WSW of Cotati, CA
68 km (42 mi) NNW of San Francisco, CA · 17 km (10 mi) WNW of Petaluma, CA
- When
- 1:00 pm PDT on 23 June 2026 ()
- Where
- 8 km (5 mi) west-southwest of Cotati, CA · earthquakes near Cotati
- Magnitude
- M 1.5 (md)
- Depth
- -0.1 km below the surface
- Felt
- no reports yet
- Nearest
- Sonoma County, 26 km NNW
- Nearest mapped fault
- San Andreas fault, 17 km from its surface trace — near is not the same as on
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 135 days ago
Earthquake alerts for Cotati, CA
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Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.
At this magnitude and depth, people at rest would likely notice it out to about 10 km (6 mi) from the epicentre. In Cotati, 8 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.
Likely felt in: Rohnert Park 9 km, intensity II. Estimated for each town centre; each link is that town's own record.
USGS catalogues this as quarry blast, not an earthquake.
How big was it?
This earthquake released about 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
- Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
- Around the size people start to feel M 3.0 180× the energy of this one
- This earthquake M 1.5 about 5.4 lb of TNT
Energy from the Gutenberg–Richter relation (log10E = 1.5M + 4.8), rounded to two figures; bar length is magnitude, which is already a logarithm of energy. Magnitudes of past earthquakes from the USGS catalogue.
For this area
The largest earthquake within 50 km since 2016 was M 4.4 on 2022-09-14 — about 22,000 times the energy of this one.
Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:
- 6.0 The 2014 South Napa, California Earthquake · 44 km ESE of this epicentre
- 5.3 3 km E of Bloomfield, California · 1 km NW of this epicentre
- 5.3 Northern California · 3 km WNW of this epicentre
Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.
Where
Epicentre 38.3100, -122.7990. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Sonoma County, CA | 26 km (16 mi) | NNW | earthquakes near Sonoma County |
| Marin County, CA | 29 km (18 mi) | S | earthquakes near Marin County |
| Napa County, CA | 47 km (29 mi) | ENE | earthquakes near Napa County |
| San Francisco County, CA | 68 km (42 mi) | SSW | earthquakes near San Francisco County |
| Solano County, CA | 75 km (47 mi) | E | earthquakes near Solano County |
| Contra Costa County, CA | 86 km (53 mi) | ESE | earthquakes near Contra Costa County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
46 earthquakes have been recorded within 50 km since this one.
- 1.7 3 km SSW of Anderson Springs, CA
- 1.1 4 km SW of Anderson Springs, CA
- 2.2 8 km W of Cotati, CA
- 2.0 7 km WSW of Calistoga, CA
- 2.6 6 km W of Yountville, CA
- 1.4 8 km WSW of The Geysers, CA
- 2.2 5 km SW of Yountville, CA
- 2.4 1 km SSW of Novato, CA
- 1.1 3 km SW of Anderson Springs, CA
- 1.2 4 km SE of The Geysers, CA
- 1.2 2 km E of Black Point-Green Point, CA
- 0.7 4 km SW of Anderson Springs, CA
- 1.7 5 km N of Healdsburg, CA
- 2.2 5 km SW of Yountville, CA
- 1.0 4 km E of St. Helena, CA
Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of . QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.
On USGS
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.