QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

Earthquake near Cayucos, CA

No earthquake was likely felt in Cayucos in the 24 hours to 3:15 am PST (11:15 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 1.5 earthquake was recorded 15 km (9 mi) north of Cayucos, CA, at 5:43 pm PDT on 28 May 2020 (00:43 UTC), 4.3 km deep.

USGS: 15km N of Cayucos, CA

82 km (51 mi) NNW of Santa Maria, CA

5:43 pm PDT, May 28, 2020 · · 4.3 km deep · released about 5.7 lb of TNT

10 km30 km60 km120 km N San Luis Obispo County 44 kmMonterey County 84 kmKings County 110 kmSan Benito County 116 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
5:43 pm PDT on 28 May 2020 ()
Where
15 km (9 mi) north of Cayucos, CA · earthquakes near Cayucos
Magnitude
M 1.5 (md)
Depth
4.3 km below the surface
Felt
no reports yet
Nearest
San Luis Obispo County, 44 km ESE
Nearest mapped fault
Hosgri fault, 20 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 2352 days ago

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

At this magnitude and depth, people at rest would likely notice it out to about 9 km (6 mi) from the epicentre. In Cayucos, 15 km away, the estimate is intensity II (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.

Earthquakes near other towns within 30 km: Templeton, Lake Nacimiento, Paso Robles, Cambria, Atascadero, Morro Bay.

How big was it?

This earthquake released about 5.7 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 2,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.7 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 8 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 10 km NE of San Simeon, California · 24 km NW of this epicentre
  2. 6.2 28km NW of Cambria, CA · 44 km WNW of this epicentre
  3. 5.8 1934 Parkfield, California Earthquake · 35 km NNE of this epicentre
  4. 5.7 Southwest of Cambria, California · 30 km WSW of this epicentre
  5. 5.2 26km NNW of Lake Nacimiento, CA · 43 km NNW 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 35.5778, -120.8777. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Luis Obispo County, CA 44 km (27 mi) ESE earthquakes near San Luis Obispo County
Monterey County, CA 84 km (52 mi) NNW earthquakes near Monterey County
Kings County, CA 110 km (69 mi) ENE earthquakes near Kings County
San Benito County, CA 116 km (72 mi) N earthquakes near San Benito County
Santa Barbara County, CA 139 km (86 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

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

  1. 3.0 5km S of Shandon, CA
  2. 1.7 16km NNW of San Simeon, CA
  3. 1.8 22km N of San Simeon, CA
  4. 1.7 12km NNE of Cayucos, CA
  5. 1.5 4km E of Avila Beach, CA
  6. 1.6 4km SW of Paso Robles, CA
  7. 1.7 6km E of Atascadero, CA
  8. 2.1 11km NE of San Simeon, CA
  9. 2.1 24km NNW of San Simeon, CA
  10. 1.6 11km W of Templeton, CA
  11. 1.6 11km W of Templeton, CA
  12. 1.6 11km W of Templeton, CA
  13. 1.7 11km NNE of Cayucos, CA
  14. 2.9 11km NNE of Cayucos, CA
  15. 1.6 12km NNE 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.