QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Paso Robles, CA

No earthquake was likely felt in Paso Robles in the 24 hours to 9:59 pm PST (05:59 UTC). The last one was M 2.5, 21 km (13 mi) S, at 11:41 pm PDT on 15 August 2026, estimated intensity II (weak) in town; 61 felt reports to USGS. Every earthquake near Paso Robles

This page: a magnitude 1.8 earthquake was recorded 48 km (30 mi) west-northwest of Paso Robles, CA, at 3:11 am PDT on 16 August 2023 (10:11 UTC), 8.8 km deep.

USGS: 14 km N of San Simeon, CA

3:11 am PDT, Aug 16, 2023 · · 8.8 km deep · released about 14 lb of TNT

Every earthquake near Paso Robles Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Monterey County 54 kmSan Luis Obispo County 80 kmSan Benito County 94 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
3:11 am PDT on 16 August 2023 ()
Where
48 km (30 mi) west-northwest of Paso Robles, CA · earthquakes near Paso Robles
Magnitude
M 1.8 (md)
Depth
8.8 km below the surface
Felt
no reports yet
Nearest
Monterey County, 54 km NNW
Nearest mapped fault
San Simeon fault, 9 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 1183 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 10 km (6 mi) from the epicentre. In Paso Robles, 48 km away, the estimate is intensity I (not felt). 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: Cambria, Lake Nacimiento.

How big was it?

This earthquake released about 14 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 1,100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 760,000× the energy of this one
  3. Around the size people start to feel M 3.0 68× the energy of this one
  4. This earthquake M 1.8 about 14 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

The largest earthquake within 50 km since 2016 was M 4.7 on 2021-10-25 — about 20,000 times the energy of this one.

Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 10 km NE of San Simeon, California · 12 km SE of this epicentre
  2. 6.2 28km NW of Cambria, CA · 13 km WSW of this epicentre
  3. 5.8 1934 Parkfield, California Earthquake · 49 km E of this epicentre
  4. 5.7 Southwest of Cambria, California · 30 km S of this epicentre
  5. 5.2 26km NNW of Lake Nacimiento, CA · 29 km NE 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 35.7670, -121.1978. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Monterey County, CA 54 km (33 mi) NNW earthquakes near Monterey County
San Luis Obispo County, CA 80 km (50 mi) ESE earthquakes near San Luis Obispo County
San Benito County, CA 94 km (59 mi) N earthquakes near San Benito County

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

Aftershocks so far

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

  1. 1.7 24 km NNW of San Simeon, CA
  2. 1.8 6 km WSW of Templeton, CA
  3. 2.0 26 km NNW of San Simeon, CA
  4. 1.9 23 km NW of San Simeon, CA
  5. 1.8 21 km N of San Simeon, CA
  6. 2.9 26 km NNW of San Simeon, CA
  7. 2.0 17 km SSE of Lopez Point, CA
  8. 1.6 3 km W of San Ardo, CA
  9. 1.7 16 km SE of Lopez Point, CA
  10. 1.8 12 km NNW of San Simeon, CA
  11. 1.6 7 km ENE of San Simeon, CA
  12. 2.1 14 km NE of San Simeon, CA
  13. 1.6 10 km ENE of Cayucos, CA
  14. 1.9 16 km WSW of King City, CA
  15. 2.7 12 km NNW 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.