QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

Earthquake near Livermore, CA

No earthquake was likely felt in Livermore in the 24 hours to 11:03 pm PST (07:03 UTC). The last one was M 2.1, 12 km (8 mi) SE, at 8:52 am PDT on 27 October 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Livermore

This page: a magnitude 2.8 earthquake was recorded 19 km (12 mi) southeast of Livermore, CA, at 1:47 pm PDT on 22 June 2021 (20:47 UTC), 1.1 km deep. 23 people have reported feeling it to USGS.

USGS: 20km SE of Livermore, CA

37 km (23 mi) NNE of San Jose, CA · 19 km (12 mi) SE of Livermore, CA

1:47 pm PDT, Jun 22, 2021 · · 1.1 km deep · released about 420 lb of TNT

10 km30 km60 km120 km N Alameda County 29 kmSanta Clara County 41 kmSan Joaquin County 49 kmContra Costa County 50 kmStanislaus County 52 kmSan Mateo County 71 kmSanta Cruz County 73 kmSolano County 83 kmMerced County 88 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
1:47 pm PDT on 22 June 2021 ()
Where
19 km (12 mi) southeast of Livermore, CA · earthquakes near Livermore
Magnitude
M 2.8 (md)
Depth
1.1 km below the surface
Felt
23 reports · strongest reported intensity III
Nearest
Alameda County, 29 km WNW
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 1903 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 26 km (16 mi) from the epicentre. In Livermore, 19 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: Livermore 19 km, intensity II · Tracy 23 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 420 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 36,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 26,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.3× the energy of this one
  4. This earthquake M 2.8 about 420 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 4.3 on 2019-07-16 — about 210 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.2 Near San Jose, California · 36 km SSW of this epicentre
  2. 6.2 The 1984 Morgan Hill, California Earthquake · 31 km SSW of this epicentre
  3. 6.1 Near San Jose, California · 46 km SSW of this epicentre
  4. 5.8 The 1980 Livermore, California Earthquake · 33 km NNW of this epicentre
  5. 5.7 15 km NE of East Foothills, California · 14 km SW 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 37.5777, -121.5905. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alameda County, CA 29 km (18 mi) WNW earthquakes near Alameda County
Santa Clara County, CA 41 km (25 mi) SSW earthquakes near Santa Clara County
San Joaquin County, CA 49 km (30 mi) NE earthquakes near San Joaquin County
Contra Costa County, CA 50 km (31 mi) NW earthquakes near Contra Costa County
Stanislaus County, CA 52 km (32 mi) E earthquakes near Stanislaus County
San Mateo County, CA 71 km (44 mi) WSW earthquakes near San Mateo County

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

Aftershocks so far

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

  1. 1.9 4km SW of Newark, CA
  2. 2.5 9km ENE of Milpitas, CA
  3. 1.7 5km NW of Dublin, CA
  4. 1.5 3km NNW of Union City, CA
  5. 1.6 5km NW of Dublin, CA
  6. 2.4 9km ESE of Fremont, CA
  7. 1.5 6km WNW of Dublin, CA
  8. 3.1 6km WNW of Dublin, CA
  9. 2.3 8km ESE of Fremont, CA
  10. 2.9 10km NE of Milpitas, CA
  11. 1.8 1km NW of Diablo, CA
  12. 1.7 6km WNW of Dublin, CA
  13. 1.9 10km NE of Milpitas, CA
  14. 2.0 14km N of Morgan Hill, CA
  15. 1.7 5km NW of Dublin, 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.