QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8ml

16km W of Simmler, CA

· 7.5 km deep · released about 550 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Luis Obispo County 24 kmKings County 85 kmSanta Barbara County 93 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 2.8 (ml)
Depth
7.5 km below the surface
Felt
2 reports · strongest reported intensity III
Nearest
San Luis Obispo County, 24 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1510 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 2 people have reported feeling it to USGS.

How big was it?

This earthquake released about 550 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 28,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 19,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.7× the energy of this one
  4. This earthquake M 2.8 about 550 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 35.3672, -120.1807. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Luis Obispo County, CA 24 km (15 mi) E of here earthquakes near San Luis Obispo County
Kings County, CA 85 km (53 mi) SSW of here earthquakes near Kings County
Santa Barbara County, CA 93 km (58 mi) N of here earthquakes near Santa Barbara County
Monterey County, CA 141 km (88 mi) SE of here earthquakes near Monterey County
Ventura County, CA 147 km (92 mi) NW of here earthquakes near Ventura County

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

Aftershocks so far

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

  1. 1.8 38 km SW of Alpaugh, CA
  2. 1.8 15 km NE of Arroyo Grande, CA
  3. 1.7 8 km ESE of San Luis Obispo, CA
  4. 1.9 4 km W of Santa Margarita, CA
  5. 1.5 11 km E of San Luis Obispo, CA
  6. 2.5 16 km W of Simmler, CA
  7. 1.6 5 km SE of Cholame, CA
  8. 1.9 6 km SE of Cholame, CA
  9. 1.5 6 km ESE of Atascadero, CA
  10. 1.5 4 km NW of San Luis Obispo, CA
  11. 2.3 23 km NNW of Simmler, CA
  12. 1.5 13 km ENE of Cholame, CA
  13. 1.8 28 km S of Kettleman City, CA
  14. 1.5 18 km ESE of Santa Margarita, CA
  15. 1.5 5 km SE of Atascadero, 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.