QuakeIndex

Earthquake · reviewed by a seismologist

M 2.0md

Earthquake near Oakley, CA

No earthquake was likely felt in Oakley in the 24 hours to 2:43 am PST (10:43 UTC). The last one was M 3.0, 16 km (10 mi) SSW, at 6:47 am PDT on 14 September 2026, estimated intensity II (weak) in town; 52 felt reports to USGS. Every earthquake near Oakley

This page: a magnitude 2.0 earthquake was recorded in Oakley, CA, at 1:00 am PDT on 22 June 2018 (08:00 UTC), 7.4 km deep.

USGS: 2km SW of Oakley, CA

6 km (4 mi) E of Antioch, CA · 6 km (4 mi) N of Brentwood, CA

1:00 am PDT, Jun 22, 2018 · · 7.4 km deep · released about 30 lb of TNT

10 km30 km60 km120 km N Contra Costa County 21 kmSolano County 36 kmSan Joaquin County 40 kmAlameda County 41 kmSacramento County 61 kmNapa County 78 kmYolo County 79 kmStanislaus County 79 kmSanta Clara County 85 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
1:00 am PDT on 22 June 2018 ()
Where
in Oakley, CA · earthquakes near Oakley
Magnitude
M 2.0 (md)
Depth
7.4 km below the surface
Felt
no reports yet
Nearest
Contra Costa County, 21 km WSW
Nearest mapped fault
Greenville fault, 16 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 3064 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 14 km (9 mi) from the epicentre. 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: Oakley in town, intensity II · Brentwood 7 km, intensity II · Antioch 7 km, intensity II · Discovery Bay 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 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 4.4 on 2018-01-04 — about 3,700 times the energy of this one.

Before 2016, the USGS record lists 4 earthquakes of M5 or more within 50 km:

  1. 5.8 The 1980 Livermore, California Earthquake · 17 km SSW of this epicentre
  2. 5.4 South of Elmira, California · 38 km NNW of this epicentre
  3. 5.4 9 km NE of Livermore, California · 26 km S of this epicentre
  4. 5.1 11 km E of Blackhawk, California · 20 km SSW 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 37.9867, -121.7245. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Contra Costa County, CA 21 km (13 mi) WSW earthquakes near Contra Costa County
Solano County, CA 36 km (23 mi) NNW earthquakes near Solano County
San Joaquin County, CA 40 km (25 mi) E earthquakes near San Joaquin County
Alameda County, CA 41 km (26 mi) SSW earthquakes near Alameda County
Sacramento County, CA 61 km (38 mi) NNE earthquakes near Sacramento County
Napa County, CA 78 km (49 mi) NW earthquakes near Napa 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. 1.5 16km SSE of Livermore, CA
  2. 1.7 2km E of Hayward, CA
  3. 1.6 2km W of Diablo, CA
  4. 1.6 4km NE of Vallejo, CA
  5. 1.8 2km NE of San Ramon, CA
  6. 2.0 14km N of Pittsburg, CA
  7. 2.2 1km NNW of Alamo, CA
  8. 1.6 2km SW of Diablo, CA
  9. 1.5 3km ESE of Berkeley, CA
  10. 1.7 3km NW of Diablo, CA
  11. 2.3 16km SSE of Livermore, CA
  12. 1.6 4km NNW of San Leandro, CA
  13. 1.8 6km ESE of San Ramon, CA
  14. 1.6 6km ESE of San Ramon, CA
  15. 1.6 9km WSW of Brentwood, 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.