QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

10km NE of Morgan Hill, CA

· 5.1 km deep · released about 1.5 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Clara County 10 kmSanta Cruz County 43 kmAlameda County 58 kmStanislaus County 66 kmSan Mateo County 74 kmMerced County 76 kmSan Benito County 78 kmSan Joaquin County 87 kmContra Costa County 87 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 3.3 (ml)
Depth
5.1 km below the surface
Felt
140 reports · strongest reported intensity IV
Nearest
Santa Clara County, 10 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1433 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 140 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1.5 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 5,100× the energy of this one
  3. Magna, Utah 2020 M 5.7 3,600× the energy of this one
  4. This earthquake M 3.3 about 1.5 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 3.1× 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 37.1923, -121.5807. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Clara County, CA 10 km (6 mi) ESE of here earthquakes near Santa Clara County
Santa Cruz County, CA 43 km (27 mi) ENE of here earthquakes near Santa Cruz County
Alameda County, CA 58 km (36 mi) SSE of here earthquakes near Alameda County
Stanislaus County, CA 66 km (41 mi) SW of here earthquakes near Stanislaus County
San Mateo County, CA 74 km (46 mi) ESE of here earthquakes near San Mateo County
Merced County, CA 76 km (47 mi) W of here earthquakes near Merced County

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

Aftershocks so far

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

  1. 2.2 6km S of San Juan Bautista, CA
  2. 1.6 15km E of Seven Trees, CA
  3. 2.2 2km W of Tres Pinos, CA
  4. 2.5 3km WSW of San Juan Bautista, CA
  5. 1.9 3km WSW of Cupertino, CA
  6. 1.7 2km ENE of Aromas, CA
  7. 1.6 6km SW of Ridgemark, CA
  8. 1.7 28km ENE of Alum Rock, CA
  9. 1.8 9km ENE of Morgan Hill, CA
  10. 3.4 14km ESE of Alum Rock, CA
  11. 1.5 4km S of Sunol, CA
  12. 2.8 10km NE of San Martin, CA
  13. 1.5 7km NE of San Martin, CA
  14. 1.7 2km ENE of Aromas, CA
  15. 2.9 5km N of Hollister, 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 4.2 on 2021-01-17 — it released about 20 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.