QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

6km NE of Ridgemark, CA

· 9.8 km deep · released about 43 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Benito County 33 kmSanta Clara County 54 kmSanta Cruz County 65 kmMerced County 65 kmMonterey County 67 kmStanislaus County 84 kmAlameda County 104 kmSan Mateo 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 2.1 (md)
Depth
9.8 km below the surface
Felt
no reports yet
Nearest
San Benito County, 33 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1577 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 43 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 5.8 350,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 250,000× 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 43 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 36.8463, -121.3103. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Benito County, CA 33 km (20 mi) NW of here earthquakes near San Benito County
Santa Clara County, CA 54 km (33 mi) SE of here earthquakes near Santa Clara County
Santa Cruz County, CA 65 km (40 mi) ESE of here earthquakes near Santa Cruz County
Merced County, CA 65 km (40 mi) SW of here earthquakes near Merced County
Monterey County, CA 67 km (42 mi) N of here earthquakes near Monterey County
Stanislaus County, CA 84 km (52 mi) SSW of here earthquakes near Stanislaus 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. 2.2 1km ENE of Hollister, CA
  2. 1.9 5km N of Pinnacles, CA
  3. 1.9 8km NNW of Pinnacles, CA
  4. 2.6 8km NW of Pinnacles, CA
  5. 1.8 7km NE of Ridgemark, CA
  6. 1.5 7km NE of Ridgemark, CA
  7. 2.3 24km NE of Pinnacles, CA
  8. 1.8 5km WSW of Ridgemark, CA
  9. 1.9 7km NW of Pinnacles, CA
  10. 3.0 10km ESE of Gilroy, CA
  11. 1.9 13km S of Tres Pinos, CA
  12. 1.5 5km N of Pinnacles, CA
  13. 1.7 10km NW of Pinnacles, CA
  14. 1.9 4km S of San Juan Bautista, CA
  15. 2.1 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 4.7 on 2019-10-15 — it released about 8,200 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.