QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near Penn Valley, CA

No earthquake was likely felt in Penn Valley in the 24 hours to 2:20 pm PST (22:20 UTC). The last one was M 5.6, 176 km (110 mi) W, at 8:10 am PDT on 24 June 2026, estimated intensity III (weak) in town; 5,311 felt reports to USGS. Every earthquake near Penn Valley

This page: a magnitude 2.3 earthquake was recorded 8 km (5 mi) west-southwest of Penn Valley, CA, at 5:46 pm PDT on 1 July 2020 (00:46 UTC), 17 km deep.

USGS: 8km WSW of Penn Valley, CA

68 km (43 mi) NNE of Sacramento, CA · 32 km (20 mi) E of Yuba City, CA

5:46 pm PDT, Jul 1, 2020 · · 17 km deep · released about 82 lb of TNT

Every earthquake near Penn Valley Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Yuba County 13 kmSutter County 39 kmNevada County 46 kmPlacer County 49 kmButte County 62 kmYolo County 76 kmEl Dorado County 77 kmSierra County 79 kmSacramento County 80 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
5:46 pm PDT on 1 July 2020 ()
Where
8 km (5 mi) west-southwest of Penn Valley, CA · earthquakes near Penn Valley
Magnitude
M 2.3 (md)
Depth
17 km below the surface
Felt
no reports yet
Nearest
Yuba County, 13 km NNW
Nearest mapped fault
Foothills fault system, 4 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 1648 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 Penn Valley, 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.

Earthquakes near other towns within 30 km: Beale Air Force Base, Lake Wildwood, Grass Valley, Loma Rica, Wheatland, Sheridan.

How big was it?

This earthquake released about 82 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 180,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 12× the energy of this one
  4. This earthquake M 2.3 about 82 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 5 earthquakes of M5 or more within 50 km:

  1. 5.9 West of Downieville, California · 44 km NNE of this epicentre
  2. 5.7 The 1975 Oroville, California Earthquake · 38 km NW of this epicentre
  3. 5.2 4 km E of Palermo, California · 35 km NNW of this epicentre
  4. 5.1 5 km ENE of Palermo, California · 36 km NNW of this epicentre
  5. 5.0 Nevada County, California · 42 km NE 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 39.1657, -121.2785. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Yuba County, CA 13 km (8 mi) NNW earthquakes near Yuba County
Sutter County, CA 39 km (25 mi) WSW earthquakes near Sutter County
Nevada County, CA 46 km (29 mi) ENE earthquakes near Nevada County
Placer County, CA 49 km (31 mi) ESE earthquakes near Placer County
Butte County, CA 62 km (39 mi) NNW earthquakes near Butte County
Yolo County, CA 76 km (47 mi) SW earthquakes near Yolo County

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

Aftershocks so far

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

  1. 2.0 6 km E of Challenge-Brownsville, CA
  2. 2.1 7 km ESE of Challenge-Brownsville, CA
  3. 1.8 1 km WSW of Granite Bay, CA
  4. 2.1 2 km WSW of Granite Bay, CA
  5. 2.6 2 km NW of Granite Bay, CA
  6. 2.2 9 km SSW of South Yuba City, CA
  7. 1.8 8 km NNE of Oroville East, CA
  8. 1.7 8 km NNE of Oroville East, CA
  9. 2.5 12 km WSW of Lincoln, CA
  10. 2.3 13 km NNE of Rio Linda, CA
  11. 2.8 11 km WSW of Lincoln, CA
  12. 2.2 13 km WSW of Lincoln, CA
  13. 2.1 12 km NW of Roseville, CA
  14. 1.8 11 km SW of Lincoln, CA
  15. 2.2 12 km WSW of Lincoln, 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.