QuakeIndex

Earthquake · reviewed by a seismologist

M 2.0md

Earthquake near Penngrove, CA

USGS: 6 km ENE of Penngrove, California

9 km (6 mi) NNE of Petaluma, CA · 62 km (39 mi) NNW of San Francisco, CA

8:15 am PDT, Sep 25, 2016 · · 8.0 km deep · released about 28 lb of TNT

10 km30 km60 km120 km N Napa County 31 kmMarin County 33 kmSonoma County 37 kmSolano County 57 kmContra Costa County 72 kmYolo County 72 kmSan Francisco County 76 kmLake County 89 kmAlameda County 96 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
8:15 am PDT on 25 September 2016 ()
Where
7 km (4 mi) ENE of Penngrove, CA · earthquakes near Penngrove
Magnitude
M 2.0 (md)
Depth
8.0 km below the surface
Felt
no reports yet
Nearest
Napa County, 31 km NE
Nearest mapped fault
Bennett Valley fault, 3 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 3521 days ago

A magnitude 2.0 earthquake was recorded 7 km (4 mi) ENE of Penngrove, CA, at 8:15 am PDT on 25 September 2016 (15:15 UTC). This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

Earthquakes near other towns within 30 km: Eldridge, El Verano, Agua Caliente, Fetters Hot Springs-Agua Caliente, Rohnert Park, Boyes Hot Springs.

How big was it?

This earthquake released about 28 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 540,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 380,000× the energy of this one
  3. Around the size people start to feel M 3.0 34× the energy of this one
  4. This earthquake M 2.0 about 28 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 6.0 The 2014 South Napa, California Earthquake · 27 km ESE of this epicentre
  2. 5.3 3 km E of Bloomfield, California · 19 km W of this epicentre
  3. 5.3 Northern California · 20 km W 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 38.3197, -122.5930. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Napa County, CA 31 km (19 mi) NE earthquakes near Napa County
Marin County, CA 33 km (20 mi) SSW earthquakes near Marin County
Sonoma County, CA 37 km (23 mi) NW earthquakes near Sonoma County
Solano County, CA 57 km (36 mi) E earthquakes near Solano County
Contra Costa County, CA 72 km (45 mi) SE earthquakes near Contra Costa County
Yolo County, CA 72 km (45 mi) NE earthquakes near Yolo County

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

Aftershocks so far

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

  1. 2.2 7 km NNW of Kenwood, California
  2. 1.9 7 km S of Cobb, California
  3. 1.8 8 km S of Cobb, California
  4. 1.8 9 km E of Angwin, California
  5. 1.7 7 km S of Cobb, California
  6. 1.6 7 km W of Middletown, California
  7. 1.8 7 km W of Middletown, California
  8. 1.9 3 km WNW of Middletown, California
  9. 2.4 3 km ENE of Vallejo, California
  10. 1.7 8 km S of Cobb, California
  11. 1.7 7 km S of Cobb, California
  12. 1.5 6 km E of Rohnert Park, California
  13. 1.7 3 km N of Larkfield-Wikiup, California
  14. 1.8 8 km S of Cobb, California
  15. 2.0 7 km S 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.