QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

24km NNW of Simmler, CA

· 7.9 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 37 kmKings County 63 kmSanta Barbara County 113 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
7.9 km below the surface
Felt
no reports yet
Nearest
San Luis Obispo County, 37 km WSW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1357 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 35.5538, -120.0978. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
San Luis Obispo County, CA 37 km (23 mi) ENE of here earthquakes near San Luis Obispo County
Kings County, CA 63 km (39 mi) SSW of here earthquakes near Kings County
Santa Barbara County, CA 113 km (70 mi) N of here earthquakes near Santa Barbara County
Monterey County, CA 134 km (83 mi) SE of here earthquakes near Monterey County
Tulare County, CA 140 km (87 mi) WSW of here earthquakes near Tulare County
San Benito County, CA 147 km (92 mi) SE of here earthquakes near San Benito County

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

Aftershocks so far

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

  1. 1.7 6 km NNW of Cholame, CA
  2. 1.7 2 km S of Avenal, CA
  3. 1.9 2 km SE of Avenal, CA
  4. 2.9 2 km SSE of Avenal, CA
  5. 1.8 25 km SW of Alpaugh, CA
  6. 1.7 5 km ESE of Cholame, CA
  7. 1.5 7 km S of Kettleman City, CA
  8. 1.9 24 km ESE of Santa Margarita, CA
  9. 1.9 4 km S of Kettleman City, CA
  10. 2.1 4 km S of Kettleman City, CA
  11. 2.4 11km SSE of Parkfield, CA
  12. 1.8 10km ESE of Kettleman City, CA
  13. 1.8 11km S of Kettleman City, CA
  14. 1.6 2km NE of Cholame, CA
  15. 1.6 2km N of Cholame, 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 4.3 on 2019-12-17 — it released about 5,600 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.