QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

4km SSW of Cupertino, CA

· 7.3 km deep · released about 16 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Cruz County 31 kmSanta Clara County 32 kmSan Mateo County 32 kmAlameda County 41 kmContra Costa County 70 kmStanislaus County 96 kmSan Joaquin County 98 kmSan Francisco County 100 kmMarin County 105 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 1.8 (md)
Depth
7.3 km below the surface
Felt
no reports yet
Nearest
Santa Cruz County, 31 km S
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1349 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 16 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 930,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 660,000× the energy of this one
  3. Around the size people start to feel M 3.0 59× the energy of this one
  4. This earthquake M 1.8 about 16 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.

Where

Epicentre 37.2923, -122.0410. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Cruz County, CA 31 km (19 mi) N of here earthquakes near Santa Cruz County
Santa Clara County, CA 32 km (20 mi) WNW of here earthquakes near Santa Clara County
San Mateo County, CA 32 km (20 mi) ESE of here earthquakes near San Mateo County
Alameda County, CA 41 km (26 mi) SSW of here earthquakes near Alameda County
Contra Costa County, CA 70 km (44 mi) S of here earthquakes near Contra Costa County
Stanislaus County, CA 96 km (60 mi) WSW of here earthquakes near Stanislaus County

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

Aftershocks so far

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

  1. 3.0 16km E of Seven Trees, CA
  2. 1.6 11km N of Morgan Hill, CA
  3. 1.5 5km NE of San Martin, CA
  4. 2.0 18km SSE of Livermore, CA
  5. 1.6 13km SSE of Livermore, CA
  6. 2.9 19km SSE of Livermore, CA
  7. 1.6 1km SSE of Portola Valley, CA
  8. 2.4 12km NNE of Alum Rock, CA
  9. 2.1 15km E of Seven Trees, CA
  10. 1.9 9km NE of Corralitos, CA
  11. 2.2 13km NE of Milpitas, CA
  12. 1.5 1km WNW of Corralitos, CA
  13. 1.8 16km E of Seven Trees, CA
  14. 2.4 14km N of Morgan Hill, CA
  15. 1.6 12km ENE of Milpitas, 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 72,000 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.