Earthquake · reviewed by a seismologist
M 1.7ml
Earthquake near Fillmore, CA
No earthquake was likely felt in Fillmore in the 24 hours to 4:40 am PST (12:40 UTC). The last one was M 3.8, 14 km (9 mi) E, at 8:00 pm PDT on 29 September 2026, estimated intensity III (weak) in town; 199 felt reports to USGS. Every earthquake near Fillmore
This page: a magnitude 1.7 earthquake was recorded 19 km (12 mi) north of Fillmore, CA, at 9:27 pm PST on 4 January 2021 (05:27 UTC), less than 1 km deep.
USGS: 19km N of Fillmore, CA
76 km (47 mi) NW of Los Angeles, CA · 36 km (23 mi) NNW of Simi Valley, CA
- When
- 9:27 pm PST on 4 January 2021 ()
- Where
- 19 km (12 mi) north of Fillmore, CA · earthquakes near Fillmore
- Magnitude
- M 1.7 (ml)
- Depth
- 0.3 km below the surface
- Felt
- no reports yet
- Nearest
- Ventura County, 32 km SW
- Nearest mapped fault
- Santa Ynez fault, under 1 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 2127 days ago
Earthquake alerts for Fillmore, CA
Get a notification in this browser when USGS records an earthquake near Fillmore, 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 12 km (7 mi) from the epicentre. In Fillmore, 19 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: Piru, Val Verde, Castaic, Frazier Park, Santa Paula, Valencia.
How big was it?
This earthquake released about 9.3 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.
- Mineral, Virginia 2011 M 5.8 1,600,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
- Around the size people start to feel M 3.0 100× the energy of this one
- This earthquake M 1.7 about 9.3 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 4.1 on 2016-03-12 — about 5,100 times the energy of this one.
Before 2016, the USGS record lists 22 earthquakes of M5 or more within 50 km; the five largest:
- 7.5 The 1952 Kern County, California Earthquake · 44 km NNW of this epicentre
- 6.0 Tejon Pass, California · 36 km N of this epicentre
- 5.9 1km ENE of Granada Hills, California · 49 km SE of this epicentre
- 5.8 13km WNW of Grapevine, CA · 47 km NNW of this epicentre
- 5.6 7km NNE of Simi Valley, California · 33 km SSE 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 34.5725, -118.8935. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Ventura County, CA | 32 km (20 mi) | SW | earthquakes near Ventura County |
| Los Angeles County, CA | 71 km (44 mi) | SE | earthquakes near Los Angeles County |
| Kern County, CA | 87 km (54 mi) | N | earthquakes near Kern County |
| Santa Barbara County, CA | 105 km (65 mi) | W | earthquakes near Santa Barbara County |
| Orange County, CA | 143 km (89 mi) | SE | earthquakes near Orange 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 3km SSE of Piru, CA
- 2.3 13km WSW of Ojai, CA
- 2.1 18km N of Fillmore, CA
- 1.8 10km ESE of Ojai, CA
- 1.7 21km SSW of Frazier Park, CA
- 1.5 17km N of Fillmore, CA
- 1.6 17km NNW of Neenach, CA
- 1.7 13km N of Piru, CA
- 1.6 11km NNW of Piru, CA
- 2.1 12km NNW of Piru, CA
- 1.6 16km SW of Frazier Park, CA
- 1.7 3km WNW of Sylmar, CA
- 1.5 8km WNW of Lake Hughes, CA
- 1.8 20km N of Fillmore, CA
- 1.6 3km NW of Frazier Park, 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.