QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near San Jose, CA

No earthquake was likely felt in San Jose in the 24 hours to 2:08 pm PST (22:08 UTC). The last one was M 2.6, 19 km (12 mi) E, at 12:38 pm PDT on 27 October 2026, estimated intensity II (weak) in town; 8 felt reports to USGS. Every earthquake near San Jose

This page: a magnitude 1.9 earthquake was recorded 30 km (19 mi) northeast of San Jose, CA, at 8:51 am PDT on 17 July 2023 (15:51 UTC), 7.4 km deep.

USGS: 24 km NE of Alum Rock, CA

28 km (18 mi) NE of San Jose, CA · 24 km (15 mi) SSE of Livermore, CA

8:51 am PDT, Jul 17, 2023 · · 7.4 km deep · released about 18 lb of TNT

Every earthquake near San Jose Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Alameda County 31 kmSanta Clara County 31 kmStanislaus County 55 kmContra Costa County 55 kmSan Joaquin County 57 kmSanta Cruz County 64 kmSan Mateo County 67 kmMerced County 86 kmSolano County 90 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
8:51 am PDT on 17 July 2023 ()
Where
30 km (19 mi) northeast of San Jose, CA · earthquakes near San Jose
Magnitude
M 1.9 (md)
Depth
7.4 km below the surface
Felt
no reports yet
Nearest
Alameda County, 31 km WNW
Nearest mapped fault
Greenville fault, 9 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 1211 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 12 km (7 mi) from the epicentre. In San Jose, 30 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.

Earthquakes near other towns within 30 km: East Foothills, Livermore, Milpitas, Pleasanton.

How big was it?

This earthquake released about 18 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 840,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 600,000× the energy of this one
  3. Around the size people start to feel M 3.0 53× the energy of this one
  4. This earthquake M 1.9 about 18 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 5.1 on 2022-10-25 — about 65,000 times the energy of this one.

Before 2016, the USGS record lists 16 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 Near Morgan Hill, California · 43 km S of this epicentre
  2. 6.2 Near San Jose, California · 27 km SW of this epicentre
  3. 6.2 The 1984 Morgan Hill, California Earthquake · 22 km SSW of this epicentre
  4. 6.1 Near San Jose, California · 37 km SSW of this epicentre
  5. 5.8 The 1979 Coyote Lake, California Earthquake · 45 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 37.4993, -121.6208. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Alameda County, CA 31 km (19 mi) WNW earthquakes near Alameda County
Santa Clara County, CA 31 km (20 mi) S earthquakes near Santa Clara County
Stanislaus County, CA 55 km (34 mi) E earthquakes near Stanislaus County
Contra Costa County, CA 55 km (34 mi) NNW earthquakes near Contra Costa County
San Joaquin County, CA 57 km (36 mi) NNE earthquakes near San Joaquin County
Santa Cruz County, CA 64 km (40 mi) SSW earthquakes near Santa Cruz County

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

Aftershocks so far

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

  1. 3.0 10 km WSW of Patterson, CA
  2. 1.5 17 km WSW of Patterson, CA
  3. 1.5 18 km WSW of Patterson, CA
  4. 1.5 18 km SW of Westley, CA
  5. 2.0 17 km WSW of Patterson, CA
  6. 2.0 14 km WSW of Patterson, CA
  7. 3.1 16 km WSW of Patterson, CA
  8. 1.8 17 km WSW of Patterson, CA
  9. 2.1 17 km WSW of Patterson, CA
  10. 1.8 11 km WSW of Patterson, CA
  11. 3.0 16 km WSW of Patterson, CA
  12. 1.6 16 km SW of Westley, CA
  13. 2.3 16 km WSW of Patterson, CA
  14. 2.0 16 km WSW of Patterson, CA
  15. 1.6 15 km SW of Westley, 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.