QuakeIndex

quarry blast · reviewed by a seismologist

M 1.5md

2 km ENE of Cayucos, California

· -0.3 km deep · released about 5.4 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Luis Obispo County 38 kmMonterey County 97 kmKings County 117 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 1.5 (md)
Depth
-0.3 km below the surface
Felt
no reports yet
Nearest
San Luis Obispo County, 38 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3442 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

USGS catalogues this as quarry blast, not an earthquake.

How big was it?

This earthquake released about 5.4 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 180× the energy of this one
  4. This earthquake M 1.5 about 5.4 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 35.4523, -120.8663. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Luis Obispo County, CA 38 km (24 mi) W of here earthquakes near San Luis Obispo County
Monterey County, CA 97 km (60 mi) SSE of here earthquakes near Monterey County
Kings County, CA 117 km (73 mi) SW of here earthquakes near Kings County
Santa Barbara County, CA 127 km (79 mi) NW 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

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

  1. 2.2 15km W of Lake Nacimiento, CA
  2. 1.6 8km ENE of San Simeon, CA
  3. 2.0 12km NE of San Simeon, CA
  4. 1.6 6 km E of Atascadero, California
  5. 2.5 9 km SW of Oak Shores, California
  6. 1.7 8 km SW of Oak Shores, California
  7. 1.8 7 km E of Atascadero, California
  8. 2.6 9 km SW of Oak Shores, California
  9. 1.9 11 km NNE of Cambria, California
  10. 1.6 11 km NNE of Cayucos, California
  11. 2.7 8 km SW of Oak Shores, California
  12. 1.6 6 km E of Atascadero, California
  13. 1.9 10 km S of Oak Shores, California
  14. 2.0 13 km N of San Simeon, California
  15. 1.8 7 km ENE of San Simeon, California

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.