QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Patterson, CA

No earthquake was likely felt in Patterson in the 24 hours to 9:16 pm PST (05:16 UTC). The last one was M 2.9, 29 km (18 mi) W, at 9:44 am PDT on 31 October 2026, estimated intensity II (weak) in town. Every earthquake near Patterson

This page: a magnitude 1.8 earthquake was recorded 24 km (15 mi) southwest of Patterson, CA, at 3:58 pm PDT on 5 April 2024 (22:58 UTC), less than 1 km deep.

USGS: 24 km SW of Patterson, CA

46 km (28 mi) E of San Jose, CA · 41 km (26 mi) NE of Gilroy, CA

3:58 pm PDT, Apr 5, 2024 · · -0.3 km deep · released about 16 lb of TNT

10 km30 km60 km120 km N Santa Clara County 36 kmStanislaus County 39 kmMerced County 52 kmAlameda County 67 kmSan Joaquin County 71 kmSanta Cruz County 71 kmSan Benito County 79 kmContra Costa County 90 kmSan Mateo 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
3:58 pm PDT on 5 April 2024 ()
Where
24 km (15 mi) southwest of Patterson, CA · earthquakes near Patterson
Magnitude
M 1.8 (md)
Depth
-0.3 km below the surface
Felt
no reports yet
Nearest
Santa Clara County, 36 km WSW
Nearest mapped fault
Ortigalita 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 944 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 Patterson, 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: Newman, Gustine.

How big was it?

This earthquake released about 16 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 5.8 930,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 660,000× the energy of this one
  3. Around the size people start to feel M 3.0 59× the energy of this one
  4. This earthquake M 1.8 about 16 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 72,000 times the energy of this one.

Before 2016, the USGS record lists 11 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 Near Morgan Hill, California · 37 km SW of this epicentre
  2. 6.2 Near San Jose, California · 44 km W of this epicentre
  3. 6.2 The 1984 Morgan Hill, California Earthquake · 34 km W of this epicentre
  4. 6.1 Near San Jose, California · 46 km WSW of this epicentre
  5. 5.8 The 1979 Coyote Lake, California Earthquake · 29 km SW 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 37.3007, -121.2975. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Clara County, CA 36 km (22 mi) WSW earthquakes near Santa Clara County
Stanislaus County, CA 39 km (24 mi) NE earthquakes near Stanislaus County
Merced County, CA 52 km (32 mi) ESE earthquakes near Merced County
Alameda County, CA 67 km (41 mi) NW earthquakes near Alameda County
San Joaquin County, CA 71 km (44 mi) N earthquakes near San Joaquin County
Santa Cruz County, CA 71 km (44 mi) WSW earthquakes near Santa Cruz County

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

Aftershocks so far

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

  1. 3.4 10 km ESE of Gilroy, CA
  2. 3.3 10 km ESE of Gilroy, CA
  3. 2.5 10 km ESE of Gilroy, CA
  4. 1.7 8 km ENE of Gilroy, CA
  5. 1.6 13 km NNE of Morgan Hill, CA
  6. 1.6 13 km SSE of Livermore, CA
  7. 1.6 13 km SSE of Livermore, CA
  8. 2.5 13 km SSE of Livermore, CA
  9. 1.8 10 km ESE of Gilroy, CA
  10. 1.8 16 km ESE of Seven Trees, CA
  11. 2.8 16 km E of Seven Trees, CA
  12. 2.1 8 km NE of Alum Rock, CA
  13. 1.7 16 km E of Seven Trees, CA
  14. 2.0 12 km ESE of Alum Rock, CA
  15. 1.6 16 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.