QuakeIndex

Earthquake · reviewed by a seismologist

M 3.5mw

7 km SW of Atascadero, CA

· 7.2 km deep · released about 2.5 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Luis Obispo County 25 kmMonterey County 104 kmKings County 108 kmSanta Barbara 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 3.5 (mw)
Depth
7.2 km below the surface
Felt
901 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
San Luis Obispo County, 25 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 193 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 901 people have reported feeling it to USGS.

How big was it?

This earthquake released about 2.5 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 68,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 3,000× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,100× the energy of this one
  4. This earthquake M 3.5 about 2.5 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 5.2× 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 35.4375, -120.7225. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Luis Obispo County, CA 25 km (16 mi) WNW of here earthquakes near San Luis Obispo County
Monterey County, CA 104 km (65 mi) SSE of here earthquakes near Monterey County
Kings County, CA 108 km (67 mi) SW of here earthquakes near Kings County
Santa Barbara County, CA 118 km (73 mi) NNW of here earthquakes near Santa Barbara County

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

Aftershocks so far

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

  1. 1.9 7 km W of Templeton, CA
  2. 1.9 7 km W of Templeton, CA
  3. 1.7 11 km NE of San Simeon, CA
  4. 2.1 6 km E of San Luis Obispo, CA
  5. 1.6 5 km ENE of San Simeon, CA
  6. 1.7 8 km ESE of Atascadero, CA
  7. 2.2 8 km N of Cambria, CA
  8. 1.8 11 km ENE of San Simeon, CA
  9. 1.8 8 km N of Cambria, CA
  10. 2.3 9 km N of Cambria, CA
  11. 1.8 7 km SW of Atascadero, CA
  12. 1.9 7 km SW of Atascadero, CA
  13. 2.0 12 km NNE of Cayucos, CA
  14. 1.8 7 km SW of Atascadero, CA
  15. 2.8 7 km W of Templeton, 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.