QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5md

Earthquake near Morgan Hill, CA

No earthquake was likely felt in Morgan Hill in the 24 hours to 3:34 pm PST (23:34 UTC). The last one was M 2.6, 20 km (13 mi) N, at 12:38 pm PDT on 27 October 2026, estimated intensity II (weak) in town; 8 felt reports to USGS. Every earthquake near Morgan Hill

This page: a magnitude 2.5 earthquake was recorded 14 km (8 mi) north of Morgan Hill, CA, at 12:15 pm PDT on 1 August 2023 (19:15 UTC), 4.9 km deep. 6 people have reported feeling it to USGS.

USGS: 14 km N of Morgan Hill, CA

17 km (10 mi) ESE of San Jose, CA

12:15 pm PDT, Aug 1, 2023 · · 4.9 km deep · released about 160 lb of TNT

Every earthquake near Morgan Hill Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Clara County 6 kmSanta Cruz County 43 kmAlameda County 50 kmStanislaus County 65 kmSan Mateo County 68 kmContra Costa County 79 kmMerced County 81 kmSan Joaquin County 82 kmSan Benito County 86 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
12:15 pm PDT on 1 August 2023 ()
Where
14 km (8 mi) north of Morgan Hill, CA · earthquakes near Morgan Hill
Magnitude
M 2.5 (md)
Depth
4.9 km below the surface
Felt
6 reports · strongest reported intensity III
Nearest
Santa Clara County, 6 km WSW
Nearest mapped fault
Calaveras fault, under 1 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 1131 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 21 km (13 mi) from the epicentre. In Morgan Hill, 14 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: Morgan Hill 14 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 160 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 95,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 68,000× the energy of this one
  3. Around the size people start to feel M 3.0 6× the energy of this one
  4. This earthquake M 2.5 about 160 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 7,400 times the energy of this one.

Before 2016, the USGS record lists 24 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.9 The 1989 Loma Prieta, California Earthquake · 33 km SW of this epicentre
  2. 6.5 Near Morgan Hill, California · 16 km S of this epicentre
  3. 6.2 Near San Jose, California · 16 km WNW of this epicentre
  4. 6.2 The 1984 Morgan Hill, California Earthquake · 8 km NNW of this epicentre
  5. 6.1 Near San Jose, California · 16 km WSW 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 37.2518, -121.6322. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Santa Clara County, CA 6 km (4 mi) WSW earthquakes near Santa Clara County
Santa Cruz County, CA 43 km (26 mi) SW earthquakes near Santa Cruz County
Alameda County, CA 50 km (31 mi) NNW earthquakes near Alameda County
Stanislaus County, CA 65 km (41 mi) ENE earthquakes near Stanislaus County
San Mateo County, CA 68 km (42 mi) WNW earthquakes near San Mateo County
Contra Costa County, CA 79 km (49 mi) NNW earthquakes near Contra Costa County

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

Aftershocks so far

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

  1. 2.0 11 km WSW of Patterson, CA
  2. 1.9 11 km SSW of Westley, CA
  3. 1.6 18 km WSW of Patterson, CA
  4. 1.6 2 km ENE of Aromas, CA
  5. 1.6 11 km W of Patterson, CA
  6. 3.0 10 km WSW of Patterson, CA
  7. 1.5 17 km WSW of Patterson, CA
  8. 1.5 18 km WSW of Patterson, CA
  9. 1.5 18 km SW of Westley, CA
  10. 2.0 17 km WSW of Patterson, CA
  11. 2.0 14 km WSW of Patterson, CA
  12. 3.1 16 km WSW of Patterson, CA
  13. 1.8 17 km WSW of Patterson, CA
  14. 2.1 17 km WSW of Patterson, CA
  15. 1.8 11 km WSW of Patterson, 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.