Earthquake · reviewed by a seismologist
M 3.1ml
Earthquake near Sierra Madre, CA
No earthquake was likely felt in Sierra Madre in the 24 hours to 4:34 am PST (12:34 UTC). The last one was M 3.8, 70 km (44 mi) WNW, at 8:00 pm PDT on 29 September 2026, estimated intensity II (weak) in town; 199 felt reports to USGS. Every earthquake near Sierra Madre
This page: a magnitude 3.1 earthquake was recorded 6 km (4 mi) northeast of Sierra Madre, CA, at 3:08 pm PDT on 8 June 2023 (22:08 UTC), 14 km deep. 120 people have reported feeling it to USGS.
USGS: 6km NE of Sierra Madre, CA
9 km (5 mi) NNE of Arcadia, CA · 42 km (26 mi) ENE of Los Angeles, CA
- When
- 3:08 pm PDT on 8 June 2023 ()
- Where
- 6 km (4 mi) northeast of Sierra Madre, CA · earthquakes near Sierra Madre
- Magnitude
- M 3.1 (ml)
- Depth
- 14 km below the surface
- Felt
- 120 reports · strongest reported intensity III
- Measured shaking
- intensity III (ShakeMap)
- Nearest
- Los Angeles County, 23 km W
- Nearest mapped fault
- Sierra Madre fault, 3 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 1188 days ago
Earthquake alerts for Sierra Madre, CA
Get a notification in this browser when USGS records an earthquake near Sierra Madre, 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 small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.
At this magnitude and depth, people at rest would likely notice it out to about 38 km (24 mi) from the epicentre. In Sierra Madre, 6 km away, the estimate is intensity III (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.
Likely felt in: Sierra Madre 6 km, intensity III · Monrovia 7 km, intensity III · Arcadia 8 km, intensity III · Altadena 11 km, intensity III · Temple City 12 km, intensity III · Azusa 13 km, intensity III · Pasadena 14 km, intensity II · Baldwin Park 14 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 1,200 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.
- Northridge, California 1994 M 6.7 280,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 12,000× the energy of this one
- Magna, Utah 2020 M 5.7 8,800× the energy of this one
- This earthquake M 3.1 about 1,200 lb of TNT
- Around the size people start to feel M 3.0 this one released 1.3× 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.
For this area
The largest earthquake within 50 km since 2016 was M 4.5 on 2020-09-19 — about 160 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 · 48 km W of this epicentre
- 6.6 1971 San Fernando Earthquake, California · 40 km NW of this epicentre
- 5.9 The 1987 Whittier Narrows, California Earthquake · 17 km SSW of this epicentre
- 5.9 1km ENE of Granada Hills, California · 45 km W of this epicentre
- 5.8 10km SSW of Agua Dulce, CA · 40 km NW 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 34.2075, -118.0125. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Los Angeles County, CA | 23 km (14 mi) | W | earthquakes near Los Angeles County |
| Orange County, CA | 63 km (39 mi) | SSE | earthquakes near Orange County |
| Ventura County, CA | 104 km (65 mi) | W | earthquakes near Ventura County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
37 earthquakes have been recorded within 50 km since this one.
- 1.9 9 km SW of Lytle Creek, CA
- 1.6 2 km NE of Vincent, CA
- 1.5 3 km NNE of Baldwin Hills, CA
- 2.6 1 km SSE of View Park-Windsor Hills, CA
- 1.9 7 km N of Rancho Cucamonga, CA
- 1.6 4 km NNE of Baldwin Hills, CA
- 2.7 3 km E of Carson, CA
- 2.7 4 km ENE of Inglewood, CA
- 1.6 5 km NE of View Park-Windsor Hills, CA
- 1.7 4 km ESE of Gardena, CA
- 2.1 3 km NNE of Granada Hills, CA
- 1.7 10 km E of Santa Clarita, CA
- 1.7 1 km ENE of Lennox, CA
- 1.9 5 km SE of Ontario, CA
- 1.8 4km SW of Compton, 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.