Earthquake · reviewed by a seismologist
M 1.5md
Earthquake near Paso Robles, CA
No earthquake was likely felt in Paso Robles in the 24 hours to 1:30 pm PST (21:30 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 1.5 earthquake was recorded 43 km (27 mi) west-northwest of Paso Robles, CA, at 4:57 am PST on 16 December 2021 (12:57 UTC), 3.7 km deep.
USGS: 21km NNE of San Simeon, CA
- When
- 4:57 am PST on 16 December 2021 ()
- Where
- 43 km (27 mi) west-northwest of Paso Robles, CA · earthquakes near Paso Robles
- Magnitude
- M 1.5 (md)
- Depth
- 3.7 km below the surface
- Felt
- no reports yet
- Nearest
- Monterey County, 50 km NNW
- Nearest mapped fault
- San Simeon fault, 18 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 1792 days ago
Earthquake alerts for Paso Robles, CA
Get a notification in this browser when USGS records an earthquake near Paso Robles, CA. No account or email needed.
Alerts are on for .
Not a warning. An alert comes after USGS publishes a quake, usually minutes after the shaking. For early warning use ShakeAlert, through your phone's Wireless Emergency Alerts or the MyShake app.
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 Paso Robles, 43 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: Lake Nacimiento, Cambria.
How big was it?
This earthquake released about 5.4 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.
- Mineral, Virginia 2011 M 5.8 2,800,000× the energy of this one
- Magna, Utah 2020 M 5.7 2,000,000× the energy of this one
- Around the size people start to feel M 3.0 180× the energy of this one
- This earthquake M 1.5 about 5.4 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 53,000 times the energy of this one.
Before 2016, the USGS record lists 9 earthquakes of M5 or more within 50 km; the five largest:
- 6.5 10 km NE of San Simeon, California · 13 km S of this epicentre
- 6.2 28km NW of Cambria, CA · 22 km WSW of this epicentre
- 5.8 1934 Parkfield, California Earthquake · 40 km E of this epicentre
- 5.7 Southwest of Cambria, California · 36 km SSW of this epicentre
- 5.2 26km NNW of Lake Nacimiento, CA · 19 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 35.8183, -121.1093. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Monterey County, CA | 50 km (31 mi) | NNW | earthquakes near Monterey County |
| San Luis Obispo County, CA | 77 km (48 mi) | SE | earthquakes near San Luis Obispo County |
| San Benito County, CA | 88 km (55 mi) | N | earthquakes near San Benito County |
| Kings County, CA | 120 km (74 mi) | ENE | earthquakes near Kings County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
44 earthquakes have been recorded within 50 km since this one.
- 2.1 20km SSE of Lopez Point, CA
- 1.7 12km NNE of Cambria, CA
- 1.8 25km NW of San Simeon, CA
- 1.9 0km NNE of Lopez Point, CA
- 1.9 1km E of Lopez Point, CA
- 1.7 22km NNW of San Simeon, CA
- 1.7 25km NW of San Simeon, CA
- 1.9 23km S of Lopez Point, CA
- 1.6 2km SE of Cayucos, CA
- 1.8 15km ENE of San Simeon, CA
- 3.0 24km SSE of Lopez Point, CA
- 2.2 24km NW of San Simeon, CA
- 1.5 7km NNE of San Simeon, CA
- 2.2 23km SSE of Lopez Point, CA
- 2.0 24km SSE of Lopez Point, 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
- The official USGS event page — the source of record for every value above
- Did you feel it? Report it to USGS — reports go to USGS, not to us
- ShakeMap for this event, when USGS has produced one
QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.