QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near Modesto, CA

No earthquake was likely felt in Modesto in the 24 hours to 9:16 pm PST (05:16 UTC). The last one was M 3.5, 47 km (29 mi) WSW, at 7:21 am PDT on 27 September 2026, estimated intensity II (weak) in town; 8 felt reports to USGS. Every earthquake near Modesto

This page: a magnitude 2.3 earthquake was recorded 24 km (15 mi) west of Modesto, CA, at 6:24 am PDT on 24 October 2022 (13:24 UTC), 14 km deep. 1 person has reported feeling it to USGS.

USGS: 10km NW of Westley, CA

60 km (37 mi) NE of San Jose, CA · 19 km (12 mi) SSW of Manteca, CA

6:24 am PDT, Oct 24, 2022 · · 14 km deep · released about 85 lb of TNT

10 km30 km60 km120 km N Stanislaus County 25 kmSan Joaquin County 35 kmAlameda County 56 kmSanta Clara County 58 kmMerced County 68 kmContra Costa County 68 kmCalaveras County 90 kmSacramento County 93 kmSolano County 93 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
6:24 am PDT on 24 October 2022 ()
Where
24 km (15 mi) west of Modesto, CA · earthquakes near Modesto
Magnitude
M 2.3 (md)
Depth
14 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
Stanislaus County, 25 km ESE
Nearest mapped fault
Great Valley thrust fault system, 7 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 1479 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 14 km (9 mi) from the epicentre. In Modesto, 24 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: Ripon, Tracy, Salida, Riverdale Park, Manteca, West Modesto.

How big was it?

This earthquake released about 85 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 180,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 130,000× the energy of this one
  3. Around the size people start to feel M 3.0 11× the energy of this one
  4. This earthquake M 2.3 about 85 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 4.3 on 2019-07-16 — about 1,000 times the energy of this one.

Before 2016, the USGS record lists 7 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.2 The 1984 Morgan Hill, California Earthquake · 50 km SW of this epicentre
  2. 5.8 The 1980 Livermore, California Earthquake · 50 km WNW of this epicentre
  3. 5.7 15 km NE of East Foothills, California · 40 km WSW of this epicentre
  4. 5.5 6 km NNE of East Foothills, California · 49 km WSW of this epicentre
  5. 5.4 9 km NE of Livermore, California · 41 km WNW 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 37.6198, -121.2737. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Stanislaus County, CA 25 km (15 mi) ESE earthquakes near Stanislaus County
San Joaquin County, CA 35 km (22 mi) N earthquakes near San Joaquin County
Alameda County, CA 56 km (35 mi) W earthquakes near Alameda County
Santa Clara County, CA 58 km (36 mi) SW earthquakes near Santa Clara County
Merced County, CA 68 km (42 mi) SE earthquakes near Merced County
Contra Costa County, CA 68 km (42 mi) WNW earthquakes near Contra Costa County

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

Aftershocks so far

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

  1. 1.6 12km ENE of Milpitas, CA
  2. 1.6 12km ENE of Milpitas, CA
  3. 1.6 12km ENE of Milpitas, CA
  4. 1.8 15km E of Seven Trees, CA
  5. 2.4 16km E of Seven Trees, CA
  6. 1.5 8km SSW of Livermore, CA
  7. 2.5 8km NNE of Alum Rock, CA
  8. 1.7 10km E of Alum Rock, CA
  9. 1.6 20km NE of Alum Rock, CA
  10. 1.5 19km WSW of Gustine, CA
  11. 1.5 15km E of Seven Trees, CA
  12. 2.0 15km E of Seven Trees, CA
  13. 1.6 18km WSW of Westley, CA
  14. 1.6 3km NW of Byron, CA
  15. 2.1 12km ESE 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.