QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9mw

22km NE of San Ardo, CA

· 8.7 km deep · released about 9.6 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Monterey County 50 kmSan Benito County 55 kmKings County 86 kmSan Luis Obispo County 93 kmMerced County 112 kmFresno County 118 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 3.9 (mw)
Depth
8.7 km below the surface
Felt
131 reports · strongest reported intensity IV
Measured shaking
intensity V (ShakeMap)
USGS impact alert
green
Nearest
Monterey County, 50 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2178 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 131 people have reported feeling it to USGS.

How big was it?

This earthquake released about 9.6 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 18,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 790× the energy of this one
  3. Magna, Utah 2020 M 5.7 560× the energy of this one
  4. This earthquake M 3.9 about 9.6 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 20× more

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 36.1873, -120.7653. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Monterey County, CA 50 km (31 mi) E of here earthquakes near Monterey County
San Benito County, CA 55 km (34 mi) SSE of here earthquakes near San Benito County
Kings County, CA 86 km (54 mi) W of here earthquakes near Kings County
San Luis Obispo County, CA 93 km (58 mi) NNW of here earthquakes near San Luis Obispo County
Merced County, CA 112 km (70 mi) S of here earthquakes near Merced County
Fresno County, CA 118 km (73 mi) WSW of here earthquakes near Fresno County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

  1. 1.9 18km NW of Parkfield, CA
  2. 1.5 22km NW of Parkfield, CA
  3. 1.5 5km ESE of Pinnacles, CA
  4. 2.0 12km SE of Pinnacles, CA
  5. 1.9 14km NW of Parkfield, CA
  6. 1.7 11km E of Coalinga, CA
  7. 2.2 10km SE of Pinnacles, CA
  8. 1.8 16km NW of Parkfield, CA
  9. 2.7 24km ENE of San Ardo, CA
  10. 1.9 10km SSW of New Idria, CA
  11. 2.6 8km NW of Parkfield, CA
  12. 1.6 23km WSW of New Idria, CA
  13. 1.7 12km SE of Pinnacles, CA
  14. 2.2 22km NE of San Ardo, CA
  15. 2.9 16km SW of Cantua Creek, 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.