QuakeIndex

Earthquake · reviewed by a seismologist

M 4.0mw

8 km E of Gilroy, CA

· 2.9 km deep · released about 14 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Clara County 31 kmSanta Cruz County 47 kmSan Benito County 55 kmMerced County 70 kmStanislaus County 75 kmAlameda County 82 kmMonterey County 85 kmSan Mateo County 92 kmSan Joaquin County 106 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
Magnitude
M 4.0 (mw)
Depth
2.9 km below the surface
Felt
920 reports · strongest reported intensity IV
Measured shaking
intensity V (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Santa Clara County, 31 km NW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 4 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 920 people have reported feeling it to USGS.

How big was it?

This earthquake released about 14 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.0 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 12,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 540× the energy of this one
  3. Magna, Utah 2020 M 5.7 380× the energy of this one
  4. This earthquake M 4.0 about 14 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 30× more

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.

Where

Epicentre 36.9973, -121.4757. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Clara County, CA 31 km (19 mi) SE of here earthquakes near Santa Clara County
Santa Cruz County, CA 47 km (29 mi) E of here earthquakes near Santa Cruz County
San Benito County, CA 55 km (34 mi) NW of here earthquakes near San Benito County
Merced County, CA 70 km (44 mi) WSW of here earthquakes near Merced County
Stanislaus County, CA 75 km (47 mi) SW of here earthquakes near Stanislaus County
Alameda County, CA 82 km (51 mi) SSE of here earthquakes near Alameda County

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

Aftershocks so far

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

  1. 1.7 5 km S of San Juan Bautista, CA
  2. 1.6 5 km SW of Ridgemark, CA
  3. 1.8 5 km SW of Ridgemark, CA
  4. 1.7 6 km NNW of Hollister, CA
  5. 2.5 5 km SW of Ridgemark, CA
  6. 1.6 5 km SW of Ridgemark, CA
  7. 1.6 5 km SW of Ridgemark, CA
  8. 1.8 5 km SW of Ridgemark, CA
  9. 3.3 16 km S of Tres Pinos, CA
  10. 1.6 5 km SW of Ridgemark, CA
  11. 2.6 5 km SW of Ridgemark, CA
  12. 2.1 5 km SW of Ridgemark, CA
  13. 1.8 5 km SW of Ridgemark, CA
  14. 1.9 5 km SW of Ridgemark, CA
  15. 3.3 4 km WSW of Ridgemark, 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.

For this area

The largest earthquake within 50 km in our catalogue was M 5.1 on 2022-10-25 — it released about 42 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.