QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9ml

Earthquake near Piru, CA

No earthquake was likely felt in Piru in the 24 hours to 4:11 am PST (12:11 UTC). The last one was M 2.2, 16 km (10 mi) E, at 8:32 am PDT on 18 October 2026, estimated intensity II (weak) in town; 16 felt reports to USGS. Every earthquake near Piru

This page: a magnitude 1.9 earthquake was recorded 3 km (2 mi) southeast of Piru, CA, at 1:10 pm PDT on 23 August 2018 (20:10 UTC), 17 km deep.

USGS: 3km SE of Piru, CA

14 km (9 mi) N of Simi Valley, CA · 53 km (33 mi) NW of Los Angeles, CA

1:10 pm PDT, Aug 23, 2018 · · 17 km deep · released about 21 lb of TNT

10 km30 km60 km120 km N Ventura County 33 kmLos Angeles County 52 kmKern County 106 kmSanta Barbara County 117 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
1:10 pm PDT on 23 August 2018 ()
Where
3 km (2 mi) southeast of Piru, CA · earthquakes near Piru
Magnitude
M 1.9 (ml)
Depth
17 km below the surface
Felt
no reports yet
Nearest
Ventura County, 33 km W
Nearest mapped fault
Oak Ridge 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 3003 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Piru, 3 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: Val Verde, Fillmore, Simi Valley, Moorpark, Valencia, Castaic.

How big was it?

This earthquake released about 21 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 730,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 520,000× the energy of this one
  3. Around the size people start to feel M 3.0 46× the energy of this one
  4. This earthquake M 1.9 about 21 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 2,300 times the energy of this one.

Before 2016, the USGS record lists 17 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.7 Northridge, California, earthquake · 29 km SE of this epicentre
  2. 6.6 1971 San Fernando Earthquake, California · 37 km E of this epicentre
  3. 5.9 1km ENE of Granada Hills, California · 29 km ESE of this epicentre
  4. 5.8 10km SSW of Agua Dulce, CA · 37 km E of this epicentre
  5. 5.8 10km SSW of Agua Dulce, CA · 37 km E 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 34.3938, -118.7708. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Ventura County, CA 33 km (21 mi) W earthquakes near Ventura County
Los Angeles County, CA 52 km (32 mi) ESE earthquakes near Los Angeles County
Kern County, CA 106 km (66 mi) N earthquakes near Kern County
Santa Barbara County, CA 117 km (73 mi) W earthquakes near Santa Barbara County
Orange County, CA 121 km (75 mi) SE earthquakes near Orange County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

  1. 1.8 1km NE of Granada Hills, CA
  2. 2.8 3km ESE of Northridge, CA
  3. 1.9 10km S of Agua Dulce, CA
  4. 2.0 13km NNW of Piru, CA
  5. 2.0 4km NE of Ojai, CA
  6. 2.8 7km NW of Malibu, CA
  7. 1.8 6km SW of Sherman Oaks, CA
  8. 1.8 3km ESE of Northridge, CA
  9. 2.0 2km E of Santa Monica, CA
  10. 1.5 3km ESE of Northridge, CA
  11. 2.6 3km ESE of Northridge, CA
  12. 1.8 3km NNE of Granada Hills, CA
  13. 2.2 2km ENE of Simi Valley, CA
  14. 1.6 2km E of Canoga Park, CA
  15. 2.6 18km W of Malibu, 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.