QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near Blackhawk, CA

No earthquake was likely felt in Blackhawk in the 24 hours to 2:49 am PST (10:49 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 1.6 earthquake was recorded 5 km (3 mi) east of Blackhawk, CA, at 8:23 pm PDT on 13 June 2022 (03:23 UTC), 15 km deep. 2 people have reported feeling it to USGS.

USGS: 5km E of Blackhawk, CA

9 km (5 mi) NE of San Ramon, CA · 57 km (36 mi) N of San Jose, CA

8:23 pm PDT, Jun 13, 2022 · · 15 km deep · released about 7.8 lb of TNT

10 km30 km60 km120 km N Contra Costa County 15 kmAlameda County 19 kmSolano County 51 kmSan Joaquin County 53 kmSan Mateo County 64 kmSanta Clara County 67 kmStanislaus County 80 kmMarin County 83 kmSacramento County 84 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
8:23 pm PDT on 13 June 2022 ()
Where
5 km (3 mi) east of Blackhawk, CA · earthquakes near Blackhawk
Magnitude
M 1.6 (md)
Depth
15 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Contra Costa County, 15 km NW
Nearest mapped fault
Greenville fault, 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 1611 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 Blackhawk, 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: Diablo, San Ramon, Danville, Dublin, Clayton, Livermore.

How big was it?

This earthquake released about 7.8 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,900,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 120× the energy of this one
  4. This earthquake M 1.6 about 7.8 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 19,000 times the energy of this one.

Before 2016, the USGS record lists 6 earthquakes of M5 or more within 50 km; the five largest:

  1. 5.8 The 1980 Livermore, California Earthquake · 8 km ENE of this epicentre
  2. 5.7 15 km NE of East Foothills, California · 40 km SSE of this epicentre
  3. 5.5 6 km NNE of East Foothills, California · 43 km S of this epicentre
  4. 5.4 9 km NE of Livermore, California · 15 km ESE of this epicentre
  5. 5.3 6 km E of East Foothills, California · 48 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 37.8120, -121.8512. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 15 km (9 mi) NW earthquakes near Contra Costa County
Alameda County, CA 19 km (12 mi) SSW earthquakes near Alameda County
Solano County, CA 51 km (32 mi) N earthquakes near Solano County
San Joaquin County, CA 53 km (33 mi) ENE earthquakes near San Joaquin County
San Mateo County, CA 64 km (40 mi) SW earthquakes near San Mateo County
Santa Clara County, CA 67 km (42 mi) SSE earthquakes near Santa Clara County

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

Aftershocks so far

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

  1. 1.6 11km NE of Milpitas, CA
  2. 2.2 10km SE of Sunol, CA
  3. 2.1 10km ESE of Fremont, CA
  4. 1.8 24km SSE of Livermore, CA
  5. 1.9 8km WSW of Mountain House, CA
  6. 3.4 24km NE of Alum Rock, CA
  7. 2.1 6km NW of Bay Point, CA
  8. 1.9 2km ENE of Berkeley, CA
  9. 1.6 6km SSW of Suisun City, CA
  10. 1.8 2km SE of Pacheco, CA
  11. 1.7 3km ESE of Berkeley, CA
  12. 2.0 3km ESE of Berkeley, CA
  13. 1.7 5km E of Vallejo, CA
  14. 2.4 3km ESE of Berkeley, CA
  15. 2.9 3km ESE of Berkeley, 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.