QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

20km NE of Arroyo Grande, CA

· 9.9 km deep · released about 25 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Luis Obispo County 17 kmSanta Barbara County 85 kmKings County 108 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 1.9 (md)
Depth
9.9 km below the surface
Felt
no reports yet
Nearest
San Luis Obispo County, 17 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2298 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 25 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 620,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 440,000× the energy of this one
  3. Around the size people start to feel M 3.0 39× the energy of this one
  4. This earthquake M 1.9 about 25 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 35.2350, -120.4232. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Luis Obispo County, CA 17 km (11 mi) S of here earthquakes near San Luis Obispo County
Santa Barbara County, CA 85 km (53 mi) NNW of here earthquakes near Santa Barbara County
Kings County, CA 108 km (67 mi) SSW of here earthquakes near Kings County
Monterey County, CA 138 km (86 mi) SE of here earthquakes near Monterey County
Ventura County, CA 153 km (95 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

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

  1. 1.5 6km NNE of Santa Margarita, CA
  2. 1.8 2km ENE of Cayucos, CA
  3. 1.5 6km NE of Santa Margarita, CA
  4. 1.6 11km W of Templeton, CA
  5. 1.5 10km SSE of Orcutt, CA
  6. 1.8 8km NNE of Cayucos, CA
  7. 1.7 7km SSW of Atascadero, CA
  8. 1.8 11km ENE of Santa Maria, CA
  9. 1.9 6km SW of San Luis Obispo, CA
  10. 1.7 6km E of Atascadero, CA
  11. 1.7 6km E of Atascadero, CA
  12. 2.4 10km W of Templeton, CA
  13. 2.7 10km W of Templeton, CA
  14. 1.6 8km WSW of Atascadero, CA
  15. 1.8 10km NE of Cayucos, 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.