QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

Earthquake near Cobb, CA

Yes: an earthquake was likely felt in Cobb in the last 24 hours. M 1.6, 4 km (2 mi) W of Cobb, at 1:30 pm PST on 11 November 2026 (21:30 UTC); the estimated shaking in Cobb was intensity II (weak). Every earthquake near Cobb

This page: a magnitude 1.5 earthquake was recorded 11 km (7 mi) west-northwest of Cobb, CA, at 3:50 pm PST on 12 December 2022 (23:50 UTC), 1.3 km deep.

USGS: 11km WNW of Cobb, CA

47 km (29 mi) NNW of Santa Rosa, CA · 126 km (78 mi) NNW of San Francisco, CA

3:50 pm PST, Dec 12, 2022 · · 1.3 km deep · released about 5.7 lb of TNT

10 km30 km60 km120 km N Lake County 29 kmSonoma County 38 kmNapa County 59 kmColusa County 63 kmMendocino County 82 kmYolo County 83 kmMarin County 90 kmGlenn County 91 kmSutter County 100 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
3:50 pm PST on 12 December 2022 ()
Where
11 km (7 mi) west-northwest of Cobb, CA · earthquakes near Cobb
Magnitude
M 1.5 (md)
Depth
1.3 km below the surface
Felt
no reports yet
Nearest
Lake County, 29 km NNE
Nearest mapped fault
Konocti Bay fault, 10 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 1430 days ago

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 Cobb, 11 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.

Earthquakes near other towns within 30 km: Kelseyville, Clear Lake Riviera, Soda Bay, Cloverdale, Lower Lake, Clearlake.

How big was it?

This earthquake released about 5.7 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.

  1. Mineral, Virginia 2011 M 5.8 2,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.7 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 170,000 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 · 36 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 38.8603, -122.8360. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 29 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 63 km (39 mi) NE earthquakes near Colusa County
Mendocino County, CA 82 km (51 mi) NW earthquakes near Mendocino County
Yolo County, CA 83 km (52 mi) ESE earthquakes near Yolo County

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

Aftershocks so far

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

  1. 2.1 4km ENE of Talmage, CA
  2. 1.5 2km WSW of Anderson Springs, CA
  3. 1.5 2km W of Anderson Springs, CA
  4. 2.0 10km WNW of The Geysers, CA
  5. 1.5 2km NNE of The Geysers, CA
  6. 1.6 7km NW of The Geysers, CA
  7. 2.2 2km NNE of The Geysers, CA
  8. 1.7 6km WNW of The Geysers, CA
  9. 2.4 2km ENE of The Geysers, CA
  10. 1.6 6km NW of The Geysers, CA
  11. 1.8 2km E of The Geysers, CA
  12. 1.5 2km NNW of The Geysers, CA
  13. 1.5 3km SW of Anderson Springs, CA
  14. 1.8 5km W of Cobb, CA
  15. 2.1 2km NNW 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.