QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

11 km WSW of Ridgemark, CA

· 8.1 km deep · released about 590 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Benito County 37 kmSanta Clara County 57 kmSanta Cruz County 57 kmMonterey County 58 kmMerced County 82 kmStanislaus County 100 kmAlameda County 108 kmSan Mateo County 110 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 2.9 (md)
Depth
8.1 km below the surface
Felt
1 report · strongest reported intensity II
Nearest
San Benito County, 37 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 388 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 590 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 26,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 18,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.6× the energy of this one
  4. This earthquake M 2.9 about 590 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 36.7443, -121.4607. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Benito County, CA 37 km (23 mi) WNW of here earthquakes near San Benito County
Santa Clara County, CA 57 km (35 mi) SSE of here earthquakes near Santa Clara County
Santa Cruz County, CA 57 km (35 mi) ESE of here earthquakes near Santa Cruz County
Monterey County, CA 58 km (36 mi) NNW of here earthquakes near Monterey County
Merced County, CA 82 km (51 mi) SW of here earthquakes near Merced County
Stanislaus County, CA 100 km (62 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

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

  1. 1.7 16 km S of Tres Pinos, CA
  2. 1.5 3 km WSW of San Juan Bautista, CA
  3. 1.7 14 km SSW of Tres Pinos, CA
  4. 1.7 11 km NNE of Pinnacles, CA
  5. 2.0 3 km N of Pinnacles, CA
  6. 1.6 9 km ENE of Hollister, CA
  7. 2.2 9 km E of Pinnacles, CA
  8. 2.2 3 km NE of Day Valley, CA
  9. 2.1 12 km NW of Pinnacles, CA
  10. 2.5 11 km SSE of Pinnacles, CA
  11. 1.8 5 km ENE of Pinnacles, CA
  12. 1.6 1 km ESE of Aromas, CA
  13. 1.8 2 km E of Aromas, CA
  14. 1.5 8 km SE of Pinnacles, CA
  15. 1.7 11 km 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 600 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.