QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near Pittsburg, CA

No earthquake was likely felt in Pittsburg in the 24 hours to 3:19 am PST (11:19 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 1.9 earthquake was recorded in Pittsburg, CA, at 6:32 pm PDT on 31 May 2020 (01:32 UTC), 19 km deep.

USGS: 1km WSW of Pittsburg, CA

in Pittsburg, CA · 53 km (33 mi) ENE of San Francisco, CA

6:32 pm PDT, May 31, 2020 · · 19 km deep · released about 19 lb of TNT

10 km30 km60 km120 km N Contra Costa County 13 kmSolano County 27 kmAlameda County 42 kmSan Joaquin County 56 kmNapa County 65 kmSacramento County 67 kmYolo County 73 kmMarin County 74 kmSan Mateo 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
6:32 pm PDT on 31 May 2020 ()
Where
in Pittsburg, CA · earthquakes near Pittsburg
Magnitude
M 1.9 (md)
Depth
19 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 13 km SSW
Nearest mapped fault
Greenville fault, 8 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 2350 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. 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, Oakley.

How big was it?

This earthquake released about 19 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 790,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 560,000× the energy of this one
  3. Around the size people start to feel M 3.0 50× the energy of this one
  4. This earthquake M 1.9 about 19 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 7,700 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 · 42 km WNW of this epicentre
  2. 5.8 The 1980 Livermore, California Earthquake · 24 km SSE of this epicentre
  3. 5.4 South of Elmira, California · 30 km N of this epicentre
  4. 5.4 9 km NE of Livermore, California · 35 km SSE of this epicentre
  5. 5.1 11 km E of Blackhawk, California · 26 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 38.0258, -121.8967. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 13 km (8 mi) SSW earthquakes near Contra Costa County
Solano County, CA 27 km (17 mi) N earthquakes near Solano County
Alameda County, CA 42 km (26 mi) S earthquakes near Alameda County
San Joaquin County, CA 56 km (35 mi) E earthquakes near San Joaquin County
Napa County, CA 65 km (41 mi) NW earthquakes near Napa County
Sacramento County, CA 67 km (42 mi) NE earthquakes near Sacramento County

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

Aftershocks so far

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

  1. 1.5 4km SSE of Brentwood, CA
  2. 1.7 2km SW of Clayton, CA
  3. 1.7 6km W of Brentwood, CA
  4. 2.3 3km ENE of San Ramon, CA
  5. 1.6 9km WSW of Mountain House, CA
  6. 2.5 2km ENE of San Leandro, CA
  7. 2.6 2km ENE of Pleasant Hill, CA
  8. 2.4 2km E of Berkeley, CA
  9. 2.6 4km ESE of Berkeley, CA
  10. 2.0 7km S of Livermore, CA
  11. 1.9 7km S of Livermore, CA
  12. 2.1 4km ESE of Berkeley, CA
  13. 1.7 1km SW of Diablo, CA
  14. 2.0 6km S of Livermore, CA
  15. 2.2 7km S of Livermore, 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.