QuakeIndex

Earthquake · reviewed by a seismologist

M 3.4ml

25 km NE of Morgan Hill, CA

· 7.7 km deep · released about 1.6 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Clara County 20 kmStanislaus County 51 kmAlameda County 53 kmSanta Cruz County 57 kmMerced County 69 kmSan Joaquin County 72 kmSan Mateo County 79 kmContra Costa County 79 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
Magnitude
M 3.4 (ml)
Depth
7.7 km below the surface
Felt
31 reports · strongest reported intensity IV
Nearest
Santa Clara County, 20 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 304 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 31 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1.6 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 110,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,700× the energy of this one
  3. Magna, Utah 2020 M 5.7 3,300× the energy of this one
  4. This earthquake M 3.4 about 1.6 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 3.3× 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 37.3115, -121.4905. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Clara County, CA 20 km (13 mi) ENE of here earthquakes near Santa Clara County
Stanislaus County, CA 51 km (32 mi) WSW of here earthquakes near Stanislaus County
Alameda County, CA 53 km (33 mi) SE of here earthquakes near Alameda County
Santa Cruz County, CA 57 km (35 mi) NE of here earthquakes near Santa Cruz County
Merced County, CA 69 km (43 mi) W of here earthquakes near Merced County
San Joaquin County, CA 72 km (45 mi) SSW of here earthquakes near San Joaquin County

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

Aftershocks so far

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

  1. 1.7 6 km SW of Gilroy, CA
  2. 2.2 2 km E of Aromas, CA
  3. 2.7 8 km E of Alum Rock, CA
  4. 2.1 3 km NNE of Corralitos, CA
  5. 1.7 2 km E of Aromas, CA
  6. 1.9 13 km NNE of Morgan Hill, CA
  7. 1.9 9 km SW of Morgan Hill, CA
  8. 1.7 2 km E of Aromas, CA
  9. 2.2 25 km WSW of Patterson, CA
  10. 2.1 16 km ESE of Seven Trees, CA
  11. 1.5 2 km E of Aromas, CA
  12. 2.1 7 km SSE of Seven Trees, CA
  13. 1.6 22 km SW of Gustine, CA
  14. 1.8 14 km ENE of Milpitas, CA
  15. 2.3 9 km ENE of San Martin, 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 370 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.