QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

7km ENE of Aromas, CA

· 5.7 km deep · released about 44 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Santa Clara County 35 kmSanta Cruz County 40 kmSan Benito County 55 kmMonterey County 79 kmMerced County 82 kmAlameda County 86 kmStanislaus County 88 kmSan Mateo County 90 kmContra Costa County 116 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
5.7 km below the surface
Felt
no reports yet
Nearest
Santa Clara County, 35 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2160 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 44 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 5.8 340,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 240,000× the energy of this one
  3. Around the size people start to feel M 3.0 22× the energy of this one
  4. This earthquake M 2.1 about 44 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 36.9177, -121.5767. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Santa Clara County, CA 35 km (22 mi) SSE of here earthquakes near Santa Clara County
Santa Cruz County, CA 40 km (25 mi) ESE of here earthquakes near Santa Cruz County
San Benito County, CA 55 km (34 mi) NW of here earthquakes near San Benito County
Monterey County, CA 79 km (49 mi) NNW of here earthquakes near Monterey County
Merced County, CA 82 km (51 mi) WSW of here earthquakes near Merced County
Alameda County, CA 86 km (54 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

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

  1. 2.1 11km SW of Ridgemark, CA
  2. 3.2 11km SW of Ridgemark, CA
  3. 2.3 4km SW of Moss Landing, CA
  4. 1.9 12km S of Tres Pinos, CA
  5. 1.9 8km SSE of San Juan Bautista, CA
  6. 1.7 6km SSW of Gilroy, CA
  7. 2.4 14km S of Tres Pinos, CA
  8. 2.2 14km NNW of Pinnacles, CA
  9. 1.7 7km SW of Tres Pinos, CA
  10. 1.8 16km SSE of Tres Pinos, CA
  11. 2.1 3km SW of San Juan Bautista, CA
  12. 1.8 4km S of San Juan Bautista, CA
  13. 1.6 3km E of Aromas, CA
  14. 1.8 6km WSW of Gilroy, CA
  15. 2.1 16km NW of Pinnacles, 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 7,900 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.