QuakeIndex

Earthquake · reviewed by a seismologist

M 3.0md

Earthquake near Cobb, CA

No earthquake was likely felt in Cobb in the 24 hours to 1:05 pm PST (21:05 UTC). The last one was M 1.6, 5 km (3 mi) S, at 5:12 am PST on 10 November 2026, estimated intensity II (weak) in town. Every earthquake near Cobb

This page: a magnitude 3.0 earthquake was recorded 10 km (6 mi) west-northwest of Cobb, CA, at 1:36 pm PDT on 10 September 2026 (20:36 UTC), less than 1 km deep. 3 people have reported feeling it to USGS.

USGS: 10 km WNW of Cobb, CA

47 km (29 mi) NNW of Santa Rosa, CA · 125 km (78 mi) NNW of San Francisco, CA

1:36 pm PDT, Sep 10, 2026 · · 0.9 km deep · released about 920 lb of TNT

10 km30 km60 km120 km N Lake County 28 kmSonoma County 38 kmNapa County 59 kmColusa County 62 kmMendocino County 83 kmYolo County 83 kmMarin County 90 kmGlenn County 90 kmSutter County 99 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
1:36 pm PDT on 10 September 2026 ()
Where
10 km (6 mi) west-northwest of Cobb, CA · earthquakes near Cobb
Magnitude
M 3.0 (md)
Depth
0.9 km below the surface
Felt
3 reports · strongest reported intensity IV
Nearest
Lake County, 28 km NNE
Nearest mapped fault
Konocti Bay fault, 9 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 50 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 36 km (22 mi) from the epicentre. In Cobb, 10 km away, the estimate is intensity III (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: Cobb 10 km, intensity III · Cloverdale 17 km, intensity III · Clearlake 21 km, intensity II · Lakeport 22 km, intensity II · Healdsburg 28 km, intensity II · Upper Lake 35 km, intensity II · Windsor 35 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 920 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 370,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 16,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 12,000× the energy of this one
  4. This earthquake M 3.0 about 920 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 5.0 on 2016-12-14 — about 1,100 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.2 6 km ESE of Talmage, California · 37 km NW 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 38.8608, -122.8290. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 28 km (18 mi) NNE earthquakes near Lake County
Sonoma County, CA 38 km (24 mi) SSW earthquakes near Sonoma County
Napa County, CA 59 km (37 mi) SE earthquakes near Napa County
Colusa County, CA 62 km (39 mi) NE earthquakes near Colusa County
Mendocino County, CA 83 km (51 mi) NW earthquakes near Mendocino County
Yolo County, CA 83 km (51 mi) ESE earthquakes near Yolo County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

60 earthquakes have been recorded within 50 km since this one.

  1. 0.3 6 km WNW of Cobb, CA
  2. 0.8 1 km NW of The Geysers, CA
  3. 0.6 10 km NW of The Geysers, CA
  4. 0.5 5 km WNW of Cobb, CA
  5. 0.3 8 km NW of The Geysers, CA
  6. 0.8 6 km NW of The Geysers, CA
  7. 0.7 8 km NW of The Geysers, CA
  8. 1.1 6 km NNW of The Geysers, CA
  9. 0.4 11 km ENE of Cloverdale, CA
  10. 1.7 8 km ESE of Cloverdale, CA
  11. 1.3 6 km NW of The Geysers, CA
  12. 0.3 0 km W of The Geysers, CA
  13. 0.2 7 km W of Cobb, CA
  14. 1.8 7 km NW of The Geysers, CA
  15. 0.3 10 km WNW of The Geysers, 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.