QuakeIndex

Earthquake · reviewed by a seismologist

M 3.4mw

Earthquake near San Jose, CA

No earthquake was likely felt in San Jose in the 24 hours to 2:42 am PST (10:42 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 3.4 earthquake was recorded 14 km (9 mi) northeast of San Jose, CA, at 10:35 am PDT on 17 June 2020 (17:35 UTC), 8.2 km deep. 3,326 people have reported feeling it to USGS.

USGS: 8km NE of Alum Rock, CA

14 km (9 mi) NNE of San Jose, CA · 12 km (7 mi) E of Milpitas, CA

10:35 am PDT, Jun 17, 2020 · · 8.2 km deep · released about 1.7 tons of TNT

10 km30 km60 km120 km N Santa Clara County 22 kmAlameda County 29 kmSanta Cruz County 50 kmSan Mateo County 54 kmContra Costa County 59 kmStanislaus County 69 kmSan Joaquin County 72 kmMerced County 95 kmSolano County 96 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
10:35 am PDT on 17 June 2020 ()
Where
14 km (9 mi) northeast of San Jose, CA · earthquakes near San Jose
Magnitude
M 3.4 (mw)
Depth
8.2 km below the surface
Felt
3,326 reports · strongest reported intensity V
Measured shaking
intensity IV (ShakeMap)
Nearest
Santa Clara County, 22 km SSE
Nearest mapped fault
Calaveras 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 2027 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 55 km (34 mi) from the epicentre. In San Jose, 14 km away, the estimate is intensity III (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: Milpitas 13 km, intensity III · San Jose 14 km, intensity III · Santa Clara 18 km, intensity III · Campbell 22 km, intensity III · Sunnyvale 25 km, intensity II · Fremont 25 km, intensity II · Cupertino 26 km, intensity II · Newark 28 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.7 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 100,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,600× the energy of this one
  3. Magna, Utah 2020 M 5.7 3,200× the energy of this one
  4. This earthquake M 3.4 about 1.7 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 3.5× more

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 27 times the energy of this one.

Before 2016, the USGS record lists 20 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 43 km SSW of this epicentre
  2. 6.5 Near Morgan Hill, California · 35 km SSE of this epicentre
  3. 6.2 Near San Jose, California · 13 km SSW of this epicentre
  4. 6.2 The 1984 Morgan Hill, California Earthquake · 14 km SSE of this epicentre
  5. 6.1 Near San Jose, California · 24 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 37.4140, -121.7625. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Clara County, CA 22 km (14 mi) SSE earthquakes near Santa Clara County
Alameda County, CA 29 km (18 mi) NNW earthquakes near Alameda County
Santa Cruz County, CA 50 km (31 mi) SSW earthquakes near Santa Cruz County
San Mateo County, CA 54 km (33 mi) W earthquakes near San Mateo County
Contra Costa County, CA 59 km (36 mi) NNW earthquakes near Contra Costa County
Stanislaus County, CA 69 km (43 mi) ENE earthquakes near Stanislaus 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. 2.2 2km SW of Lexington Hills, CA
  2. 2.1 8km WSW of Mountain House, CA
  3. 2.1 10km ESE of Livermore, CA
  4. 1.5 19km SSE of Livermore, CA
  5. 1.6 8km WSW of Mountain House, CA
  6. 2.0 8km WSW of Mountain House, CA
  7. 1.5 10km NE of Milpitas, CA
  8. 1.5 12km ESE of Alum Rock, CA
  9. 3.2 3km ESE of San Leandro, CA
  10. 2.6 3km ESE of San Leandro, CA
  11. 1.7 9km WSW of Mountain House, CA
  12. 1.7 9km WSW of Mountain House, CA
  13. 2.0 10km NE of Milpitas, CA
  14. 2.3 10km NE of Milpitas, CA
  15. 1.8 10km E of Alum Rock, 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.