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 8 km (5 mi) south of Cobb, CA, at 6:52 am PST on 19 December 2016 (14:52 UTC), 1.8 km deep.

USGS: 7 km S of Cobb, California

34 km (21 mi) N of Santa Rosa, CA · 112 km (69 mi) NNW of San Francisco, CA

6:52 am PST, Dec 19, 2016 · · 1.8 km deep · released about 5.9 lb of TNT

10 km30 km60 km120 km N Sonoma County 31 kmLake County 39 kmNapa County 44 kmColusa County 63 kmYolo County 72 kmMarin County 78 kmSolano County 87 kmSutter County 94 kmMendocino County 98 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
6:52 am PST on 19 December 2016 ()
Where
8 km (5 mi) south of Cobb, CA · earthquakes near Cobb
Magnitude
M 1.5 (md)
Depth
1.8 km below the surface
Felt
no reports yet
Nearest
Sonoma County, 31 km SW
Nearest mapped fault
Maacama 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 3561 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, 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: Cobb 8 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 5.9 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 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,800,000× the energy of this one
  3. Around the size people start to feel M 3.0 160× the energy of this one
  4. This earthquake M 1.5 about 5.9 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 2 earthquakes of M5 or more within 50 km:

  1. 5.3 3 km E of Bloomfield, California · 49 km S of this epicentre
  2. 5.3 Northern California · 49 km S 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 38.7537, -122.7223. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sonoma County, CA 31 km (19 mi) SW earthquakes near Sonoma County
Lake County, CA 39 km (25 mi) N earthquakes near Lake County
Napa County, CA 44 km (27 mi) SE earthquakes near Napa County
Colusa County, CA 63 km (39 mi) NE earthquakes near Colusa County
Yolo County, CA 72 km (44 mi) E earthquakes near Yolo County
Marin County, CA 78 km (49 mi) S earthquakes near Marin County

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

Aftershocks so far

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

  1. 1.5 7 km W of Cobb, California
  2. 1.5 7 km W of Cobb, California
  3. 2.3 7 km W of Cobb, California
  4. 2.7 7 km W of Cobb, California
  5. 1.6 7 km W of Middletown, California
  6. 1.8 7 km W of Middletown, California
  7. 2.0 5 km WNW of Cobb, California
  8. 2.8 4 km SW of Cobb, California
  9. 1.9 3 km WNW of Middletown, California
  10. 2.1 9 km WNW of Cobb, California
  11. 2.1 4 km SW of Cobb, California
  12. 1.6 5 km SSE of Cobb, California
  13. 1.9 7 km W of Cobb, California
  14. 1.7 8 km S of Cobb, California
  15. 1.9 6 km W of Cobb, California

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.