QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

Earthquake near Cayucos, CA

No earthquake was likely felt in Cayucos in the 24 hours to 4:51 am PST (12:51 UTC). The last one was M 2.1, 15 km (9 mi) E, at 6:08 am PDT on 21 October 2026, estimated intensity II (weak) in town; 3 felt reports to USGS. Every earthquake near Cayucos

This page: a magnitude 2.9 earthquake was recorded 11 km (7 mi) north-northeast of Cayucos, CA, at 5:50 pm PDT on 12 August 2020 (00:50 UTC), 5.3 km deep. 37 people have reported feeling it to USGS.

USGS: 11km NNE of Cayucos, CA

75 km (46 mi) NNW of Santa Maria, CA

5:50 pm PDT, Aug 12, 2020 · · 5.3 km deep · released about 570 lb of TNT

10 km30 km60 km120 km N San Luis Obispo County 38 kmMonterey County 91 kmKings County 110 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
5:50 pm PDT on 12 August 2020 ()
Where
11 km (7 mi) north-northeast of Cayucos, CA · earthquakes near Cayucos
Magnitude
M 2.9 (md)
Depth
5.3 km below the surface
Felt
37 reports · strongest reported intensity III
Nearest
San Luis Obispo County, 38 km ESE
Nearest mapped fault
Hosgri fault, 21 km from its surface trace — near is not the same as on
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2206 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 29 km (18 mi) from the epicentre. In Cayucos, 11 km away, the estimate is intensity III (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

Likely felt in: Cayucos 11 km, intensity III · Atascadero 15 km, intensity II · Paso Robles 17 km, intensity II · Cambria 23 km, intensity II · Los Osos 24 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 570 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 27,000× 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 2.9 about 570 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.

For this area

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 5 earthquakes of M5 or more within 50 km:

  1. 6.5 10 km NE of San Simeon, California · 31 km NW of this epicentre
  2. 5.8 1934 Parkfield, California Earthquake · 38 km NNE of this epicentre
  3. 5.7 Southwest of Cambria, California · 34 km W of this epicentre
  4. 5.2 26km NNW of Lake Nacimiento, CA · 49 km NNW of this epicentre
  5. 5.1 13km N of San Miguel, CA · 40 km NNE of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 35.5275, -120.8288. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Luis Obispo County, CA 38 km (23 mi) ESE earthquakes near San Luis Obispo County
Monterey County, CA 91 km (56 mi) NNW earthquakes near Monterey County
Kings County, CA 110 km (68 mi) NE earthquakes near Kings County
Santa Barbara County, CA 132 km (82 mi) SSE earthquakes near Santa Barbara County

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

Aftershocks so far

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

  1. 1.8 8km NNE of Cayucos, CA
  2. 1.7 7km SSW of Atascadero, CA
  3. 2.6 13km NNW of San Simeon, CA
  4. 1.6 12km ENE of Cambria, CA
  5. 1.9 6km SW of San Luis Obispo, CA
  6. 1.7 6km E of Atascadero, CA
  7. 2.7 13km WSW of Parkfield, CA
  8. 1.7 6km E of Atascadero, CA
  9. 2.4 10km W of Templeton, CA
  10. 1.8 10km W of Templeton, CA
  11. 2.7 10km W of Templeton, CA
  12. 1.6 8km WSW of Atascadero, CA
  13. 1.6 13km W of Lake Nacimiento, CA
  14. 1.8 10km NE of Cayucos, CA
  15. 2.0 20km N of San Simeon, 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.