QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Pittsburg, CA

No earthquake was likely felt in Pittsburg in the 24 hours to 3:44 am PST (11:44 UTC). The last one was M 2.5, 15 km (9 mi) WSW, at 1:23 am PST on 2 November 2026, estimated intensity II (weak) in town; 39 felt reports to USGS. Every earthquake near Pittsburg

This page: a magnitude 2.1 earthquake was recorded 5 km (3 mi) south of Pittsburg, CA, at 2:09 pm PST on 28 December 2022 (22:09 UTC), 18 km deep. 1 person has reported feeling it to USGS.

USGS: 4km S of Pittsburg, CA

in Pittsburg, CA · 52 km (32 mi) ENE of San Francisco, CA

2:09 pm PST, Dec 28, 2022 · · 18 km deep · released about 40 lb of TNT

10 km30 km60 km120 km N Contra Costa County 9 kmSolano County 31 kmAlameda County 38 kmSan Joaquin County 54 kmNapa County 69 kmSacramento County 70 kmMarin County 75 kmSan Mateo County 77 kmYolo County 77 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
2:09 pm PST on 28 December 2022 ()
Where
5 km (3 mi) south of Pittsburg, CA · earthquakes near Pittsburg
Magnitude
M 2.1 (md)
Depth
18 km below the surface
Felt
1 report · strongest reported intensity I
Nearest
Contra Costa County, 9 km SW
Nearest mapped fault
Greenville fault, 5 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 1403 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Pittsburg, 5 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: Clayton, Antioch, Bay Point, Concord, Oakley, Pleasant Hill.

How big was it?

This earthquake released about 40 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 380,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 270,000× the energy of this one
  3. Around the size people start to feel M 3.0 24× the energy of this one
  4. This earthquake M 2.1 about 40 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 4.5 on 2019-10-15 — about 3,700 times the energy of this one.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 6.0 The 2014 South Napa, California Earthquake · 45 km NW of this epicentre
  2. 5.8 The 1980 Livermore, California Earthquake · 20 km SSE of this epicentre
  3. 5.4 South of Elmira, California · 35 km N of this epicentre
  4. 5.4 9 km NE of Livermore, California · 31 km SSE of this epicentre
  5. 5.1 11 km E of Blackhawk, California · 22 km SSE 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 37.9873, -121.8888. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 9 km (6 mi) SW earthquakes near Contra Costa County
Solano County, CA 31 km (20 mi) N earthquakes near Solano County
Alameda County, CA 38 km (24 mi) S earthquakes near Alameda County
San Joaquin County, CA 54 km (34 mi) E earthquakes near San Joaquin County
Napa County, CA 69 km (43 mi) NNW earthquakes near Napa County
Sacramento County, CA 70 km (44 mi) NE earthquakes near Sacramento 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. 1.6 2km S of Blackhawk, CA
  2. 2.0 2km S of Blackhawk, CA
  3. 1.8 2km S of Blackhawk, CA
  4. 2.0 2km S of Blackhawk, CA
  5. 2.2 7km SSE of Sunol, CA
  6. 1.7 2km S of San Ramon, CA
  7. 1.9 6km SW of Antioch, CA
  8. 2.0 6km SW of Antioch, CA
  9. 2.5 6km SW of Antioch, CA
  10. 1.7 5km SW of Antioch, CA
  11. 2.8 6km SW of Antioch, CA
  12. 2.2 6km SSW of Antioch, CA
  13. 2.4 6km SSW of Antioch, CA
  14. 2.3 6km SSW of Antioch, CA
  15. 2.0 9km W of Brentwood, 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.