QuakeIndex

Earthquake · reviewed by a seismologist

M 2.0md

Earthquake near Blackhawk, CA

No earthquake was likely felt in Blackhawk in the 24 hours to 2:42 am PST (10:42 UTC). The last one was M 2.1, 5 km (3 mi) WNW, at 7:18 am PDT on 31 October 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Blackhawk

This page: a magnitude 2.0 earthquake was recorded 9 km (6 mi) northeast of Blackhawk, CA, at 6:52 am PDT on 30 March 2022 (13:52 UTC), 12 km deep. 2 people have reported feeling it to USGS.

USGS: 9km NE of Blackhawk, CA

11 km (7 mi) SSW of Antioch, CA · 52 km (32 mi) ENE of San Francisco, CA

6:52 am PDT, Mar 30, 2022 · · 12 km deep · released about 30 lb of TNT

10 km30 km60 km120 km N Contra Costa County 10 kmAlameda County 28 kmSolano County 43 kmSan Joaquin County 51 kmSan Mateo County 70 kmSanta Clara County 76 kmSacramento County 76 kmNapa County 80 kmMarin 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
6:52 am PDT on 30 March 2022 ()
Where
9 km (6 mi) northeast of Blackhawk, CA · earthquakes near Blackhawk
Magnitude
M 2.0 (md)
Depth
12 km below the surface
Felt
2 reports · strongest reported intensity I
Nearest
Contra Costa County, 10 km WNW
Nearest mapped fault
Greenville fault, 1 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 1688 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 Blackhawk, 9 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, Diablo, Antioch, Brentwood, Danville, Pittsburg.

How big was it?

This earthquake released about 30 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 5.8 500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 350,000× the energy of this one
  3. Around the size people start to feel M 3.0 32× the energy of this one
  4. This earthquake M 2.0 about 30 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 4,900 times the energy of this one.

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

  1. 5.8 The 1980 Livermore, California Earthquake · 9 km SE of this epicentre
  2. 5.7 15 km NE of East Foothills, California · 48 km SSE of this epicentre
  3. 5.4 South of Elmira, California · 46 km N of this epicentre
  4. 5.4 9 km NE of Livermore, California · 20 km SE of this epicentre
  5. 5.1 11 km E of Blackhawk, California · 11 km SE 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 37.8895, -121.8490. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 10 km (6 mi) WNW earthquakes near Contra Costa County
Alameda County, CA 28 km (17 mi) SSW earthquakes near Alameda County
Solano County, CA 43 km (27 mi) N earthquakes near Solano County
San Joaquin County, CA 51 km (32 mi) E earthquakes near San Joaquin County
San Mateo County, CA 70 km (44 mi) SW earthquakes near San Mateo County
Santa Clara County, CA 76 km (47 mi) S earthquakes near Santa Clara 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. 1.8 3km NNE of San Leandro, CA
  2. 1.7 11km SE of Livermore, CA
  3. 1.8 12km SE of Livermore, CA
  4. 1.9 4km W of Pleasant Hill, CA
  5. 1.8 11km NE of Milpitas, CA
  6. 1.8 2km E of Walnut Creek, CA
  7. 1.5 4km WNW of Orinda, CA
  8. 1.6 6km WNW of Dublin, CA
  9. 1.9 3km SW of American Canyon, CA
  10. 2.5 4km SSE of Rodeo, CA
  11. 1.8 2km SSE of Alamo, CA
  12. 1.9 9km NE of Milpitas, CA
  13. 2.2 3km W of Orinda, CA
  14. 2.3 3km W of Orinda, CA
  15. 1.6 8km SSE of Suisun City, 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.