Earthquake · reviewed by a seismologist
M 3.0md
Earthquake near Shandon, CA
No earthquake was likely felt in Shandon in the 24 hours to 5:28 am PST (13:28 UTC). The last one was M 2.0, 13 km (8 mi) NE, at 3:39 pm PST on 2 December 2025, estimated intensity II (weak) in town. Every earthquake near Shandon
This page: a magnitude 3.0 earthquake was recorded 5 km (3 mi) south of Shandon, CA, at 2:58 am PDT on 17 October 2020 (09:58 UTC), 5.7 km deep. 7 people have reported feeling it to USGS.
USGS: 5km S of Shandon, CA
- When
- 2:58 am PDT on 17 October 2020 ()
- Where
- 5 km (3 mi) south of Shandon, CA · earthquakes near Shandon
- Magnitude
- M 3.0 (md)
- Depth
- 5.7 km below the surface
- Felt
- 7 reports · strongest reported intensity III
- Nearest
- San Luis Obispo County, 26 km SSW
- Nearest mapped fault
- San Juan fault, 7 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 2144 days ago
Earthquake alerts for Shandon, CA
Get a notification in this browser when USGS records an earthquake near Shandon, 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 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 35 km (22 mi) from the epicentre. In Shandon, 5 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: Paso Robles 29 km, intensity II · Atascadero 30 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 890 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.0 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 380,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 17,000× the energy of this one
- Magna, Utah 2020 M 5.7 12,000× the energy of this one
- This earthquake M 3.0 about 890 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 92 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 1922 Parkfield, California Earthquake · 19 km NE of this epicentre
- 6.4 1901 Parkfield, California Earthquake · 44 km NNW of this epicentre
- 6.0 2004 Parkfield, California Earthquake · 23 km N of this epicentre
- 5.8 1934 Parkfield, California Earthquake · 37 km NW of this epicentre
- 5.5 1966 Parkfield, California Earthquake · 21 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 35.6135, -120.3743. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| San Luis Obispo County, CA | 26 km (16 mi) | SSW | earthquakes near San Luis Obispo County |
| Kings County, CA | 72 km (45 mi) | NE | earthquakes near Kings County |
| Monterey County, CA | 110 km (68 mi) | NW | earthquakes near Monterey County |
| Santa Barbara County, CA | 124 km (77 mi) | SSE | earthquakes near Santa Barbara County |
| San Benito County, CA | 128 km (80 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
42 earthquakes have been recorded within 50 km since this one.
- 1.5 19km NW of Parkfield, CA
- 1.5 7km NNW of Cholame, CA
- 2.0 12km NW of Parkfield, CA
- 2.7 12km NW of Parkfield, CA
- 2.3 17km NW of Parkfield, CA
- 1.6 16km NW of Parkfield, CA
- 1.7 6km E of Atascadero, CA
- 1.5 17km NW of Parkfield, CA
- 1.9 16km NW of Parkfield, CA
- 1.7 16km NW of Parkfield, CA
- 2.0 14km NW of Parkfield, CA
- 2.7 13km WSW of Parkfield, CA
- 1.7 6km E of Atascadero, CA
- 1.7 18km NW of Parkfield, CA
- 2.6 18km NW of Parkfield, 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.