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 4:50 am PST (12:50 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 2 km (1 mi) northwest of Pittsburg, CA, at 11:18 am PST on 7 December 2019 (19:18 UTC), 17 km deep. 1 person has reported feeling it to USGS.

USGS: 2km NW of Pittsburg, CA

in Pittsburg, CA · 54 km (34 mi) ENE of San Francisco, CA

11:18 am PST, Dec 7, 2019 · · 17 km deep · released about 37 lb of TNT

10 km30 km60 km120 km N Contra Costa County 14 kmSolano County 25 kmAlameda County 44 kmSan Joaquin County 57 kmNapa County 63 kmSacramento County 66 kmYolo County 71 kmMarin County 74 kmSan Mateo County 81 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
11:18 am PST on 7 December 2019 ()
Where
2 km (1 mi) northwest of Pittsburg, CA · earthquakes near Pittsburg
Magnitude
M 2.1 (md)
Depth
17 km below the surface
Felt
1 report · strongest reported intensity I
Nearest
Contra Costa County, 14 km SSW
Nearest mapped fault
Greenville fault, 9 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 2526 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 1 km (1 mi) from the epicentre. In Pittsburg, 2 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: Bay Point, Antioch, Clayton, Concord, Pacheco, Vine Hill.

How big was it?

This earthquake released about 37 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 5.8 410,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 290,000× the energy of this one
  3. Around the size people start to feel M 3.0 26× the energy of this one
  4. This earthquake M 2.1 about 37 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 4,000 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 · 41 km WNW of this epicentre
  2. 5.8 The 1980 Livermore, California Earthquake · 26 km SSE of this epicentre
  3. 5.4 South of Elmira, California · 28 km N of this epicentre
  4. 5.4 9 km NE of Livermore, California · 37 km SSE of this epicentre
  5. 5.1 11 km E of Blackhawk, California · 28 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 38.0438, -121.9030. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 14 km (9 mi) SSW earthquakes near Contra Costa County
Solano County, CA 25 km (16 mi) N earthquakes near Solano County
Alameda County, CA 44 km (27 mi) S earthquakes near Alameda County
San Joaquin County, CA 57 km (35 mi) ESE earthquakes near San Joaquin County
Napa County, CA 63 km (39 mi) NW earthquakes near Napa County
Sacramento County, CA 66 km (41 mi) NE earthquakes near Sacramento County

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

Aftershocks so far

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

  1. 1.7 1km WSW of Pleasant Hill, CA
  2. 2.3 1km W of Pleasant Hill, CA
  3. 1.8 1km S of San Ramon, CA
  4. 1.7 4km NNW of Pittsburg, CA
  5. 2.4 3km NW of Pittsburg, CA
  6. 1.6 4km ENE of Walnut Creek, CA
  7. 1.6 1km N of San Pablo, CA
  8. 2.0 12km SW of Byron, CA
  9. 1.7 1km NE of Diablo, CA
  10. 2.1 1km NE of Diablo, CA
  11. 1.8 0km E of Diablo, CA
  12. 1.5 0km E of Diablo, CA
  13. 1.5 2km WNW of Concord, CA
  14. 1.6 15km N of Green Valley, CA
  15. 1.7 3km ENE of San Ramon, 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.