Earthquake · reviewed by a seismologist
M 3.8mw
4 km SE of Piru, CA
- When
- Magnitude
- M 3.8 (mw)
- Depth
- 11 km below the surface
- Felt
- 175 reports · strongest reported intensity III
- Measured shaking
- intensity III (ShakeMap)
- Nearest
- Ventura County, 34 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 2 hours ago
This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 175 people have reported feeling it to USGS.
How big was it?
This earthquake released about 7.8 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.8 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 22,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 970× the energy of this one
- Magna, Utah 2020 M 5.7 680× the energy of this one
- This earthquake M 3.8 about 7.8 tons of TNT
- Around the size people start to feel M 3.0 this one released 16× more
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.
Revisions
USGS refines a solution as more stations report. Every change we have seen is listed here.
| What changed | From | To | When |
|---|---|---|---|
| felt reports | 174 | 175 | |
| felt reports | 173 | 174 | |
| felt reports | 170 | 173 | |
| felt reports | 167 | 170 | |
| measured intensity | 3.27 | 3.36 | |
| felt reports | 166 | 167 | |
| felt reports | 164 | 166 | |
| felt reports | 162 | 164 | |
| felt reports | 158 | 162 | |
| felt reports | 155 | 158 | |
| felt reports | 144 | 155 | |
| felt reports | 132 | 144 |
Where
Epicentre 34.3952, -118.7622. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction | |
|---|---|---|---|
| Ventura County, CA | 34 km (21 mi) | E of here | earthquakes near Ventura County |
| Los Angeles County, CA | 51 km (32 mi) | WNW of here | earthquakes near Los Angeles County |
| Kern County, CA | 106 km (66 mi) | S of here | earthquakes near Kern County |
| Santa Barbara County, CA | 118 km (73 mi) | E of here | earthquakes near Santa Barbara County |
| Orange County, CA | 121 km (75 mi) | NW of here | earthquakes near Orange County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
No further earthquakes have been recorded within 50 km since this one.
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.
For this area
The largest earthquake within 50 km in our catalogue was M 5.1 on 2023-08-20 — it released about 80 times the energy of this one.
From the QuakeIndex catalogue, built from the USGS FDSN event service.
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.