QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

20km NE of Morgan Hill, CA

· 9.5 km deep · released about 37 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Clara County 17 kmSanta Cruz County 52 kmStanislaus County 56 kmAlameda County 56 kmMerced County 70 kmSan Joaquin County 78 kmSan Mateo County 78 kmSan Benito County 81 kmContra Costa County 83 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 2.1 (md)
Depth
9.5 km below the surface
Felt
no reports yet
Nearest
Santa Clara County, 17 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2406 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 37 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 410,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 290,000× the energy of this one
  3. Around the size people start to feel M 3.0 26× the energy of this one
  4. This earthquake M 2.1 about 37 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 37.2603, -121.5055. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Clara County, CA 17 km (10 mi) ENE of here earthquakes near Santa Clara County
Santa Cruz County, CA 52 km (33 mi) ENE of here earthquakes near Santa Cruz County
Stanislaus County, CA 56 km (35 mi) SW of here earthquakes near Stanislaus County
Alameda County, CA 56 km (35 mi) SE of here earthquakes near Alameda County
Merced County, CA 70 km (43 mi) W of here earthquakes near Merced County
San Joaquin County, CA 78 km (48 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

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

  1. 2.9 3km WSW of San Juan Bautista, CA
  2. 3.0 4km W of San Juan Bautista, CA
  3. 2.8 4km W of San Juan Bautista, CA
  4. 2.4 3km W of San Juan Bautista, CA
  5. 2.6 4km W of San Juan Bautista, CA
  6. 1.9 7km NNE of Tres Pinos, CA
  7. 1.8 7km NNW of Hollister, CA
  8. 2.7 5km SSW of Gilroy, CA
  9. 3.0 5km SSW of Gilroy, CA
  10. 3.9 10km ENE of Morgan Hill, CA
  11. 1.7 16km E of Seven Trees, CA
  12. 1.6 12km ESE of Gilroy, CA
  13. 1.7 6km SW of Gilroy, CA
  14. 2.2 15km E of Seven Trees, CA
  15. 1.6 2km SW of San Juan Bautista, 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 4.1 on 2017-10-10 — it released about 1,100 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.