QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

16km N of Morgan Hill, CA

· 5.2 km deep · released about 14 lb of TNT

10 km30 km60 km120 km N Santa Clara County 7 kmSanta Cruz County 43 kmAlameda County 47 kmSan Mateo County 65 kmStanislaus County 66 kmContra Costa County 76 kmSan Joaquin County 81 kmMerced County 83 kmSan Benito County 89 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
5.2 km below the surface
Felt
no reports yet
Nearest
Santa Clara County, 7 km SSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1916 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 14 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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 37.2753, -121.6533. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Clara County, CA 7 km (4 mi) NNE of here earthquakes near Santa Clara County
Santa Cruz County, CA 43 km (27 mi) NE of here earthquakes near Santa Cruz County
Alameda County, CA 47 km (29 mi) SSE of here earthquakes near Alameda County
San Mateo County, CA 65 km (41 mi) ESE of here earthquakes near San Mateo County
Stanislaus County, CA 66 km (41 mi) WSW of here earthquakes near Stanislaus County
Contra Costa County, CA 76 km (47 mi) SSE of here earthquakes near Contra Costa 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. 2.0 12km NNE of Hollister, CA
  2. 2.2 3km E of Aromas, CA
  3. 2.3 8km ESE of Fremont, CA
  4. 2.9 10km NE of Milpitas, CA
  5. 2.0 3km E of Aromas, CA
  6. 1.6 11km ESE of Gilroy, CA
  7. 1.9 10km NE of Milpitas, CA
  8. 1.5 6km SW of Gilroy, CA
  9. 2.2 6km SW of Gilroy, CA
  10. 2.0 14km N of Morgan Hill, CA
  11. 2.6 6km S of Livermore, CA
  12. 2.4 11km NE of Milpitas, CA
  13. 1.6 2km E of Aromas, CA
  14. 1.9 15km E of Seven Trees, CA
  15. 1.7 3km ESE of Aromas, 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 4,300 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.