QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

Earthquake near Gustine, CA

No earthquake was likely felt in Gustine in the 24 hours to 4:56 pm PST (00:56 UTC). The last one was M 3.1, 23 km (14 mi) WSW, at 9:18 pm PDT on 21 October 2026, estimated intensity II (weak) in town; 9 felt reports to USGS. Every earthquake near Gustine

This page: a magnitude 1.6 earthquake was recorded 19 km (12 mi) southwest of Gustine, CA, at 5:28 pm PDT on 18 June 2023 (00:28 UTC), 9.4 km deep. 1 person has reported feeling it to USGS.

USGS: 19km SW of Gustine, CA

61 km (38 mi) ESE of San Jose, CA · 41 km (25 mi) ENE of Gilroy, CA

5:28 pm PDT, Jun 18, 2023 · · 9.4 km deep · released about 8.4 lb of TNT

Every earthquake near Gustine Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Merced County 39 kmSanta Clara County 48 kmStanislaus County 48 kmSan Benito County 60 kmSanta Cruz County 77 kmAlameda County 87 kmSan Joaquin County 88 kmMonterey County 102 kmContra Costa County 111 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
5:28 pm PDT on 18 June 2023 ()
Where
19 km (12 mi) southwest of Gustine, CA · earthquakes near Gustine
Magnitude
M 1.6 (md)
Depth
9.4 km below the surface
Felt
1 report
Nearest
Merced County, 39 km E
Nearest mapped fault
Ortigalita 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 1241 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 7 km (4 mi) from the epicentre. In Gustine, 19 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, Los Banos.

How big was it?

This earthquake released about 8.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,300,000× the energy of this one
  3. Around the size people start to feel M 3.0 110× the energy of this one
  4. This earthquake M 1.6 about 8.4 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 140,000 times the energy of this one.

Before 2016, the USGS record lists 12 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 Near Morgan Hill, California · 43 km W of this epicentre
  2. 6.2 The 1984 Morgan Hill, California Earthquake · 50 km WNW of this epicentre
  3. 5.9 10 km SE of Tres Pinos, California · 46 km S of this epicentre
  4. 5.8 The 1979 Coyote Lake, California Earthquake · 32 km W of this epicentre
  5. 5.5 7 km SW of Hollister, California · 46 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 37.1448, -121.1580. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Merced County, CA 39 km (24 mi) E earthquakes near Merced County
Santa Clara County, CA 48 km (30 mi) W earthquakes near Santa Clara County
Stanislaus County, CA 48 km (30 mi) NNE earthquakes near Stanislaus County
San Benito County, CA 60 km (37 mi) S earthquakes near San Benito County
Santa Cruz County, CA 77 km (48 mi) W earthquakes near Santa Cruz County
Alameda County, CA 87 km (54 mi) NW earthquakes near Alameda 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. 1.7 16 km SW of Westley, CA
  2. 1.9 16 km SW of Westley, CA
  3. 2.4 10 km NE of Morgan Hill, CA
  4. 1.9 8 km WSW of Gilroy, CA
  5. 1.7 10 km W of Patterson, CA
  6. 2.0 7 km N of Aromas, CA
  7. 1.7 5 km SE of Tres Pinos, CA
  8. 1.5 16 km SW of Westley, CA
  9. 3.3 16 km SW of Westley, CA
  10. 1.7 8 km SSW of Ridgemark, CA
  11. 2.4 8 km SSW of Ridgemark, CA
  12. 2.5 4 km S of San Juan Bautista, CA
  13. 1.6 2 km SW of Tres Pinos, CA
  14. 1.6 10 km NNE of Hollister, CA
  15. 1.9 2 km SSW of Tres Pinos, 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.