QuakeIndex

Earthquake · reviewed by a seismologist

M 2.0md

Earthquake near Livermore, CA

No earthquake was likely felt in Livermore in the 24 hours to 4:15 am PST (12:15 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 2.0 earthquake was recorded 7 km (4 mi) south of Livermore, CA, at 10:06 am PDT on 29 September 2020 (17:06 UTC), 3.8 km deep. 4 people have reported feeling it to USGS.

USGS: 7km S of Livermore, CA

7 km (4 mi) S of Livermore, CA · 37 km (23 mi) N of San Jose, CA

10:06 am PDT, Sep 29, 2020 · · 3.8 km deep · released about 28 lb of TNT

10 km30 km60 km120 km N Alameda County 14 kmContra Costa County 37 kmSanta Clara County 45 kmSan Joaquin County 55 kmSan Mateo County 59 kmStanislaus County 67 kmSanta Cruz County 71 kmSolano County 73 kmMarin County 99 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
10:06 am PDT on 29 September 2020 ()
Where
7 km (4 mi) south of Livermore, CA · earthquakes near Livermore
Magnitude
M 2.0 (md)
Depth
3.8 km below the surface
Felt
4 reports · strongest reported intensity III
Nearest
Alameda County, 14 km WNW
Nearest mapped fault
Las Positas fault, 2 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 2229 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 15 km (9 mi) from the epicentre. In Livermore, 7 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 7 km, intensity II · Pleasanton 11 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 28 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 5.8 540,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 380,000× the energy of this one
  3. Around the size people start to feel M 3.0 34× the energy of this one
  4. This earthquake M 2.0 about 28 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 5,200 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 S of this epicentre
  2. 6.2 The 1984 Morgan Hill, California Earthquake · 35 km SSE of this epicentre
  3. 6.1 Near San Jose, California · 47 km S of this epicentre
  4. 5.8 The 1980 Livermore, California Earthquake · 24 km N of this epicentre
  5. 5.7 15 km NE of East Foothills, California · 17 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 37.6220, -121.7607. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alameda County, CA 14 km (8 mi) WNW earthquakes near Alameda County
Contra Costa County, CA 37 km (23 mi) NNW earthquakes near Contra Costa County
Santa Clara County, CA 45 km (28 mi) S earthquakes near Santa Clara County
San Joaquin County, CA 55 km (34 mi) NE earthquakes near San Joaquin County
San Mateo County, CA 59 km (36 mi) WSW earthquakes near San Mateo County
Stanislaus County, CA 67 km (42 mi) E earthquakes near Stanislaus County

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

Aftershocks so far

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

  1. 2.6 3km WNW of Concord, CA
  2. 1.8 9km ENE of Milpitas, CA
  3. 1.8 10km ESE of Livermore, CA
  4. 2.1 9km ENE of Milpitas, CA
  5. 2.0 14km SE of Livermore, CA
  6. 2.1 2km SSW of Los Altos Hills, CA
  7. 2.8 3km S of Los Altos Hills, CA
  8. 1.8 2km S of Los Altos Hills, CA
  9. 2.6 1km WNW of Bay Point, CA
  10. 2.6 16km E of Seven Trees, CA
  11. 1.9 2km NNE of San Leandro, CA
  12. 1.5 8km ENE of Alum Rock, CA
  13. 1.8 2km SE of Pacheco, CA
  14. 1.6 3km ESE of Pacheco, CA
  15. 1.6 9km NE of Milpitas, 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.