Earthquake · reviewed by a seismologist
M 1.5ml
Earthquake near Piru, CA
No earthquake was likely felt in Piru in the 24 hours to 4:03 am PST (12:03 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 1.5 earthquake was recorded 3 km (2 mi) south-southeast of Piru, CA, at 2:10 am PDT on 7 August 2021 (09:10 UTC), 10 km deep.
USGS: 3km SSE of Piru, CA
14 km (9 mi) NNW of Simi Valley, CA · 53 km (33 mi) NW of Los Angeles, CA
- When
- 2:10 am PDT on 7 August 2021 ()
- Where
- 3 km (2 mi) south-southeast of Piru, CA · earthquakes near Piru
- Magnitude
- M 1.5 (ml)
- Depth
- 10 km below the surface
- Felt
- no reports yet
- Nearest
- Ventura County, 32 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 1922 days ago
Earthquake alerts for Piru, CA
Get a notification in this browser when USGS records an earthquake near Piru, 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 2 km (1 mi) from the epicentre. 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: Fillmore, Val Verde, Simi Valley, Moorpark, Valencia, Castaic.
How big was it?
This earthquake released about 5.9 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 2,500,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,800,000× the energy of this one
- Around the size people start to feel M 3.0 160× the energy of this one
- This earthquake M 1.5 about 5.9 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 4.2 on 2020-07-30 — about 9,100 times the energy of this one.
Before 2016, the USGS record lists 17 earthquakes of M5 or more within 50 km; the five largest:
- 6.7 Northridge, California, earthquake · 30 km SE of this epicentre
- 6.6 1971 San Fernando Earthquake, California · 38 km E of this epicentre
- 5.9 1km ENE of Granada Hills, California · 29 km ESE of this epicentre
- 5.8 10km SSW of Agua Dulce, CA · 38 km E of this epicentre
- 5.8 10km SSW of Agua Dulce, CA · 38 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 34.3888, -118.7832. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Ventura County, CA | 32 km (20 mi) | W | earthquakes near Ventura County |
| Los Angeles County, CA | 52 km (33 mi) | ESE | earthquakes near Los Angeles County |
| Kern County, CA | 107 km (66 mi) | N | earthquakes near Kern County |
| Santa Barbara County, CA | 116 km (72 mi) | W | earthquakes near Santa Barbara County |
| Orange County, CA | 122 km (76 mi) | SE | earthquakes near Orange County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
43 earthquakes have been recorded within 50 km since this one.
- 2.3 8km SE of Piru, CA
- 1.6 6km W of Ojai, CA
- 2.3 3km SSE of Frazier Park, CA
- 1.7 9km SE of Piru, CA
- 1.6 6km SE of Piru, CA
- 1.7 10km NNW of Piru, CA
- 1.6 25km SSW of Frazier Park, CA
- 1.9 8km NW of Malibu, CA
- 1.9 4km WSW of Ojai, CA
- 3.2 5km WSW of Ojai, CA
- 1.7 4km SSW of Moorpark, CA
- 1.6 22km SSW of Frazier Park, CA
- 1.6 13km NNW of Piru, CA
- 2.0 8km NW of Fillmore, CA
- 3.6 8km WNW of Fillmore, 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.