QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8ml

Earthquake near Fillmore, CA

No earthquake was likely felt in Fillmore in the 24 hours to 5:44 am PST (13:44 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 1.8 earthquake was recorded 20 km (12 mi) north of Fillmore, CA, at 7:10 pm PDT on 22 May 2021 (02:10 UTC), less than 1 km deep.

USGS: 20km N of Fillmore, CA

76 km (47 mi) NW of Los Angeles, CA · 37 km (23 mi) NNW of Simi Valley, CA

7:10 pm PDT, May 22, 2021 · · 0.0 km deep · released about 14 lb of TNT

10 km30 km60 km120 km N Ventura County 33 kmLos Angeles County 72 kmKern County 87 kmSanta Barbara County 105 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
7:10 pm PDT on 22 May 2021 ()
Where
20 km (12 mi) north of Fillmore, CA · earthquakes near Fillmore
Magnitude
M 1.8 (ml)
Depth
0.0 km below the surface
Felt
no reports yet
Nearest
Ventura County, 33 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 1998 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 13 km (8 mi) from the epicentre. In Fillmore, 20 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, Lebec.

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 5.7 790,000× the energy of this one
  3. Around the size people start to feel M 3.0 70× 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 4.1 on 2016-03-12 — about 3,500 times the energy of this one.

Before 2016, the USGS record lists 23 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.5 The 1952 Kern County, California Earthquake · 43 km NNW of this epicentre
  2. 6.0 Tejon Pass, California · 36 km N of this epicentre
  3. 5.9 1km ENE of Granada Hills, California · 50 km SE of this epicentre
  4. 5.8 13km WNW of Grapevine, CA · 47 km NNW of this epicentre
  5. 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 34.5790, -118.8940. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Ventura County, CA 33 km (20 mi) SW earthquakes near Ventura County
Los Angeles County, CA 72 km (45 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 144 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

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

  1. 1.9 8km SE of Neenach, CA
  2. 1.5 11km NW of Pine Mountain Club, CA
  3. 1.6 23km NNE of Ojai, CA
  4. 1.7 9km WSW of Grapevine, CA
  5. 2.2 3km S of Frazier Park, CA
  6. 1.6 3km WNW of Sylmar, CA
  7. 1.6 2km SSE of Chatsworth, CA
  8. 1.9 10km WSW of Grapevine, CA
  9. 1.6 3km N of Sylmar, CA
  10. 1.8 12km WSW of Lake Hughes, CA
  11. 1.8 12km WSW of Lake Hughes, CA
  12. 1.7 2km SE of Simi Valley, CA
  13. 1.6 8km W of Frazier Park, CA
  14. 1.9 9km W of Grapevine, CA
  15. 2.4 13km WSW of Ojai, 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.