QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Paso Robles, CA

No earthquake was likely felt in Paso Robles in the 24 hours to 5:27 am PST (13:27 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 1.7 earthquake was recorded 4 km (2 mi) west of Paso Robles, CA, at 4:16 pm PST on 21 December 2019 (00:16 UTC), 6.1 km deep.

USGS: 5km W of Paso Robles, CA

81 km (50 mi) NNW of Santa Maria, CA

4:16 pm PST, Dec 21, 2019 · · 6.1 km deep · released about 11 lb of TNT

10 km30 km60 km120 km N San Luis Obispo County 37 kmMonterey County 86 kmKings County 97 kmSan Benito County 115 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
4:16 pm PST on 21 December 2019 ()
Where
4 km (2 mi) west of Paso Robles, CA · earthquakes near Paso Robles
Magnitude
M 1.7 (md)
Depth
6.1 km below the surface
Felt
no reports yet
Nearest
San Luis Obispo County, 37 km SE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2508 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 11 km (7 mi) from the epicentre. In Paso Robles, 4 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.

Likely felt in: Paso Robles 4 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 11 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 89× the energy of this one
  4. This earthquake M 1.7 about 11 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 4.3 on 2019-12-17 — about 7,700 times the energy of this one.

Before 2016, the USGS record lists 13 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 1922 Parkfield, California Earthquake · 46 km ENE of this epicentre
  2. 6.5 10 km NE of San Simeon, California · 34 km WNW of this epicentre
  3. 6.4 1901 Parkfield, California Earthquake · 47 km NNE of this epicentre
  4. 6.0 2004 Parkfield, California Earthquake · 40 km ENE of this epicentre
  5. 5.8 1934 Parkfield, California Earthquake · 26 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 35.6215, -120.7338. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
San Luis Obispo County, CA 37 km (23 mi) SE earthquakes near San Luis Obispo County
Monterey County, CA 86 km (54 mi) NW earthquakes near Monterey County
Kings County, CA 97 km (60 mi) ENE earthquakes near Kings County
San Benito County, CA 115 km (71 mi) NNW 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. 2.2 10km NW of Parkfield, CA
  2. 1.6 18km NW of Parkfield, CA
  3. 1.6 11km WSW of Templeton, CA
  4. 1.8 11km WSW of Templeton, CA
  5. 2.0 12km WNW of Avila Beach, CA
  6. 1.9 18km NW of Parkfield, CA
  7. 2.7 14km ENE of San Simeon, CA
  8. 1.6 25km E of San Ardo, CA
  9. 1.8 24km E of San Ardo, CA
  10. 2.2 7km WSW of Cayucos, CA
  11. 1.5 3km N of Cholame, CA
  12. 2.1 4km SW of San Ardo, CA
  13. 1.5 11km NNE of Cayucos, CA
  14. 1.7 7km W of Templeton, CA
  15. 1.6 9km NNE of Cambria, 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.