QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3mw

4km NNW of Aromas, CA

· 7.0 km deep · released about 1.1 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Cruz County 32 kmSanta Clara County 33 kmSan Benito County 62 kmMonterey County 82 kmSan Mateo County 83 kmAlameda County 83 kmMerced County 89 kmStanislaus County 92 kmContra Costa County 113 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 (mw)
Depth
7.0 km below the surface
Felt
489 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Santa Cruz County, 32 km WNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1858 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 489 people have reported feeling it to USGS.

How big was it?

This earthquake released about 1.1 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 6.7 150,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 6,700× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,700× the energy of this one
  4. This earthquake M 3.3 about 1.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.4× 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 36.9255, -121.6632. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Cruz County, CA 32 km (20 mi) ESE of here earthquakes near Santa Cruz County
Santa Clara County, CA 33 km (21 mi) S of here earthquakes near Santa Clara County
San Benito County, CA 62 km (39 mi) NW of here earthquakes near San Benito County
Monterey County, CA 82 km (51 mi) NNW of here earthquakes near Monterey County
San Mateo County, CA 83 km (52 mi) SE of here earthquakes near San Mateo County
Alameda County, CA 83 km (52 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

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

  1. 2.2 4km NNW of Hollister, CA
  2. 1.8 7km S of Tres Pinos, CA
  3. 2.7 4km NNW of Hollister, CA
  4. 1.8 12km SSW of Tres Pinos, CA
  5. 1.9 3km SSW of San Juan Bautista, CA
  6. 1.6 8km NE of Ridgemark, CA
  7. 2.0 3km SSW of San Juan Bautista, CA
  8. 1.5 8km ENE of Gilroy, CA
  9. 2.4 9km NE of San Martin, CA
  10. 1.7 2km ENE of Aromas, CA
  11. 1.7 15km E of Seven Trees, CA
  12. 1.8 16km N of Morgan Hill, CA
  13. 2.1 14km N of Morgan Hill, CA
  14. 1.7 14km N of Morgan Hill, CA
  15. 2.1 10km S 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.7 on 2019-10-15 — it released about 150 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.