QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Livermore, CA

No earthquake was likely felt in Livermore in the 24 hours to 10:29 pm PST (06:29 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 1.8 earthquake was recorded 4 km (3 mi) southeast of Livermore, CA, at 7:51 pm PDT on 17 September 2017 (02:51 UTC), 5.9 km deep.

USGS: 4 km SE of Livermore, California

in Livermore, CA · 41 km (25 mi) N of San Jose, CA

7:51 pm PDT, Sep 17, 2017 · · 5.9 km deep · released about 17 lb of TNT

10 km30 km60 km120 km N Alameda County 16 kmContra Costa County 35 kmSanta Clara County 48 kmSan Joaquin County 51 kmSan Mateo County 62 kmStanislaus County 65 kmSolano County 70 kmSanta Cruz County 76 kmSacramento County 95 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
7:51 pm PDT on 17 September 2017 ()
Where
4 km (3 mi) southeast of Livermore, CA · earthquakes near Livermore
Magnitude
M 1.8 (md)
Depth
5.9 km below the surface
Felt
no reports yet
Nearest
Alameda County, 16 km W
Nearest mapped fault
Las Positas fault, 6 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 3338 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 13 km (8 mi) from the epicentre. In Livermore, 4 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 4 km, intensity II · Pleasanton 12 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.2 Near San Jose, California · 40 km S of this epicentre
  2. 6.2 The 1984 Morgan Hill, California Earthquake · 39 km S of this epicentre
  3. 5.8 The 1980 Livermore, California Earthquake · 21 km N of this epicentre
  4. 5.7 15 km NE of East Foothills, California · 20 km SSE of this epicentre
  5. 5.5 6 km NNE of East Foothills, California · 25 km S 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 37.6560, -121.7352. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alameda County, CA 16 km (10 mi) W earthquakes near Alameda County
Contra Costa County, CA 35 km (22 mi) NNW earthquakes near Contra Costa County
Santa Clara County, CA 48 km (30 mi) S earthquakes near Santa Clara County
San Joaquin County, CA 51 km (32 mi) NE earthquakes near San Joaquin County
San Mateo County, CA 62 km (39 mi) WSW earthquakes near San Mateo County
Stanislaus County, CA 65 km (41 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 4km W of Cupertino, CA
  2. 2.5 22km W of Westley, CA
  3. 1.6 15km E of Seven Trees, CA
  4. 1.9 10km E of Alum Rock, CA
  5. 3.9 8km ENE of Alum Rock, CA
  6. 2.7 0km SW of Pacheco, CA
  7. 1.5 8km SSE of Rio Vista, CA
  8. 2.3 2km NW of Pittsburg, CA
  9. 1.6 13km SSE of Livermore, CA
  10. 2.0 15km E of Seven Trees, CA
  11. 1.6 2km E of Diablo, CA
  12. 1.8 10km E of Alum Rock, CA
  13. 1.6 6km ENE of Dublin, CA
  14. 2.0 9km ENE of Milpitas, CA
  15. 2.6 2km NNE of San Leandro, 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.