QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2md

Earthquake near Diablo, CA

No earthquake was likely felt in Diablo in the 24 hours to 3:23 am PST (11:23 UTC). The last one was M 2.5, 18 km (11 mi) NNW, at 1:23 am PST on 2 November 2026, estimated intensity II (weak) in town; 39 felt reports to USGS. Every earthquake near Diablo

This page: a magnitude 2.2 earthquake was recorded 3 km (2 mi) north-northwest of Diablo, CA, at 2:00 pm PST on 6 February 2022 (22:00 UTC), 9.0 km deep. 5 people have reported feeling it to USGS.

USGS: 3km NNW of Diablo, CA

8 km (5 mi) SE of Walnut Creek, CA · 40 km (25 mi) ENE of San Francisco, CA

2:00 pm PST, Feb 6, 2022 · · 9.0 km deep · released about 64 lb of TNT

10 km30 km60 km120 km N Contra Costa County 7 kmAlameda County 24 kmSolano County 46 kmSan Mateo County 60 kmSan Joaquin County 62 kmMarin County 71 kmSanta Clara County 75 kmNapa County 79 kmSacramento County 86 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
2:00 pm PST on 6 February 2022 ()
Where
3 km (2 mi) north-northwest of Diablo, CA · earthquakes near Diablo
Magnitude
M 2.2 (md)
Depth
9.0 km below the surface
Felt
5 reports · strongest reported intensity II
Nearest
Contra Costa County, 7 km NNE
Nearest mapped fault
Calaveras 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 1730 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 16 km (10 mi) from the epicentre. In Diablo, 3 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.

Likely felt in: Danville 4 km, intensity II · Alamo 5 km, intensity II · San Ramon 8 km, intensity II · Walnut Creek 10 km, intensity II · Pleasant Hill 13 km, intensity II · Lafayette 13 km, intensity II · Concord 14 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 64 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 230,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 170,000× the energy of this one
  3. Around the size people start to feel M 3.0 15× the energy of this one
  4. This earthquake M 2.2 about 64 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 2,300 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.0 The 2014 South Napa, California Earthquake · 50 km NW of this epicentre
  2. 5.8 The 1980 Livermore, California Earthquake · 18 km E of this epicentre
  3. 5.7 15 km NE of East Foothills, California · 49 km SSE of this epicentre
  4. 5.4 South of Elmira, California · 50 km N of this epicentre
  5. 5.4 9 km NE of Livermore, California · 26 km ESE 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 37.8557, -121.9747. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 7 km (5 mi) NNE earthquakes near Contra Costa County
Alameda County, CA 24 km (15 mi) SSE earthquakes near Alameda County
Solano County, CA 46 km (29 mi) N earthquakes near Solano County
San Mateo County, CA 60 km (37 mi) SW earthquakes near San Mateo County
San Joaquin County, CA 62 km (39 mi) E earthquakes near San Joaquin County
Marin County, CA 71 km (44 mi) WNW earthquakes near Marin 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. 1.9 2km N of Castro Valley, CA
  2. 1.6 8km ENE of Vallejo, CA
  3. 1.8 11km NE of Milpitas, CA
  4. 2.4 8km SW of Brentwood, CA
  5. 1.8 5km E of Vallejo, CA
  6. 2.3 10km SW of Brentwood, CA
  7. 1.6 10km ENE of Blackhawk, CA
  8. 1.8 3km S of Pittsburg, CA
  9. 1.9 5km ESE of Moraga, CA
  10. 2.7 4km S of Pittsburg, CA
  11. 1.9 6km SW of Clayton, CA
  12. 1.6 4km SW of San Ramon, CA
  13. 1.6 4km SW of San Ramon, CA
  14. 1.6 2km E of Pleasant Hill, CA
  15. 1.7 5km E of Vallejo, 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.