QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

11km SSW of Lake Nacimiento, CA

· 4.7 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N San Luis Obispo County 53 kmMonterey County 74 kmSan Benito County 108 kmKings County 112 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 1.8 (md)
Depth
4.7 km below the surface
Felt
no reports yet
Nearest
San Luis Obispo County, 53 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1286 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 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 730,000× the energy of this one
  3. Around the size people start to feel M 3.0 65× the energy of this one
  4. This earthquake M 1.8 about 15 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 35.6470, -120.9403. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Luis Obispo County, CA 53 km (33 mi) WNW of here earthquakes near San Luis Obispo County
Monterey County, CA 74 km (46 mi) SSE of here earthquakes near Monterey County
San Benito County, CA 108 km (67 mi) S of here earthquakes near San Benito County
Kings County, CA 112 km (70 mi) WSW of here earthquakes near Kings County

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

Aftershocks so far

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

  1. 1.9 10 km W of Atascadero, CA
  2. 1.5 18 km N of San Simeon, CA
  3. 1.6 24km NW of San Simeon, CA
  4. 1.6 18km NNW of San Simeon, CA
  5. 1.7 21km NNW of San Simeon, CA
  6. 1.7 3km ESE of San Ardo, CA
  7. 1.8 8km W of Templeton, CA
  8. 1.7 6km W of San Ardo, CA
  9. 1.6 21km NW of San Simeon, CA
  10. 1.7 14km SW of San Simeon, CA
  11. 1.6 12km NNE of Cambria, CA
  12. 1.5 12km NNW of San Simeon, CA
  13. 2.4 13km NNW of San Simeon, CA
  14. 2.9 13km NNW of San Simeon, CA
  15. 1.9 9km ENE 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.

For this area

The largest earthquake within 50 km in our catalogue was M 4.7 on 2021-10-25 — it released about 19,000 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

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