QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

Earthquake near San Jose, CA

No earthquake was likely felt in San Jose in the 24 hours to 3:29 pm PST (23:29 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 2.8 earthquake was recorded 22 km (14 mi) east-northeast of San Jose, CA, at 10:18 am PDT on 28 October 2018 (17:18 UTC), 5.0 km deep. 19 people have reported feeling it to USGS.

USGS: 15km ENE of Alum Rock, CA

19 km (12 mi) NE of San Jose, CA

10:18 am PDT, Oct 28, 2018 · · 5.0 km deep · released about 450 lb of TNT

10 km30 km60 km120 km N Santa Clara County 23 kmAlameda County 33 kmSanta Cruz County 55 kmContra Costa County 60 kmStanislaus County 61 kmSan Mateo County 62 kmSan Joaquin County 67 kmMerced County 88 kmSolano County 97 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
10:18 am PDT on 28 October 2018 ()
Where
22 km (14 mi) east-northeast of San Jose, CA · earthquakes near San Jose
Magnitude
M 2.8 (md)
Depth
5.0 km below the surface
Felt
19 reports · strongest reported intensity III
Nearest
Santa Clara County, 23 km S
Nearest mapped fault
Calaveras 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 2932 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 San Jose, 22 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: Milpitas 21 km, intensity II · San Jose 22 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 450 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 34,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 24,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.1× the energy of this one
  4. This earthquake M 2.8 about 450 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 4.1 on 2017-10-10 — about 92 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 · 47 km SSW of this epicentre
  2. 6.5 Near Morgan Hill, California · 35 km S of this epicentre
  3. 6.2 Near San Jose, California · 18 km SW of this epicentre
  4. 6.2 The 1984 Morgan Hill, California Earthquake · 13 km S of this epicentre
  5. 6.1 Near San Jose, California · 27 km SSW 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 37.4242, -121.6717. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Clara County, CA 23 km (14 mi) S earthquakes near Santa Clara County
Alameda County, CA 33 km (20 mi) NW earthquakes near Alameda County
Santa Cruz County, CA 55 km (34 mi) SSW earthquakes near Santa Cruz County
Contra Costa County, CA 60 km (37 mi) NNW earthquakes near Contra Costa County
Stanislaus County, CA 61 km (38 mi) ENE earthquakes near Stanislaus County
San Mateo County, CA 62 km (38 mi) W 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. 1.5 22km ENE of Alum Rock, CA
  2. 2.0 15km E of Seven Trees, CA
  3. 1.8 9km NE of Milpitas, CA
  4. 1.5 3km S of Loyola, CA
  5. 1.9 8km NE of Gilroy, CA
  6. 1.8 18km NE of San Martin, CA
  7. 2.2 10km ESE of Alum Rock, CA
  8. 1.6 4km S of Loyola, CA
  9. 1.9 2km NNE of Union City, CA
  10. 1.7 7km WSW of Gilroy, CA
  11. 1.6 6km SSE of Sunol, CA
  12. 2.3 4km SSW of Los Altos Hills, CA
  13. 1.7 3km S of Loyola, CA
  14. 2.0 3km NNE of Fairview, CA
  15. 2.1 17km ESE of Livermore, 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.