Earthquake · reviewed by a seismologist
M 2.0ml
Earthquake near Sierra Madre, CA
No earthquake was likely felt in Sierra Madre in the 24 hours to 2:07 pm PST (22:07 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 2.0 earthquake was recorded 11 km (7 mi) north-northeast of Sierra Madre, CA, at 12:45 pm PDT on 25 August 2020 (19:45 UTC), 12 km deep.
USGS: 11km NNE of Sierra Madre, CA
14 km (9 mi) N of Arcadia, CA · 45 km (28 mi) NE of Los Angeles, CA
- When
- 12:45 pm PDT on 25 August 2020 ()
- Where
- 11 km (7 mi) north-northeast of Sierra Madre, CA · earthquakes near Sierra Madre
- Magnitude
- M 2.0 (ml)
- Depth
- 12 km below the surface
- Felt
- no reports yet
- Nearest
- Los Angeles County, 24 km WSW
- Nearest mapped fault
- San Gabriel fault, 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 2270 days ago
Earthquake alerts for Sierra Madre, CA
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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 10 km (6 mi) from the epicentre. In Sierra Madre, 11 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: Monrovia, Bradbury, Arcadia, Altadena, Duarte, East Pasadena.
How big was it?
This earthquake released about 31 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 480,000× the energy of this one
- Magna, Utah 2020 M 5.7 340,000× the energy of this one
- Around the size people start to feel M 3.0 31× the energy of this one
- This earthquake M 2.0 about 31 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 4.4 on 2018-08-29 — about 3,600 times the energy of this one.
Before 2016, the USGS record lists 15 earthquakes of M5 or more within 50 km; the five largest:
- 6.7 Northridge, California, earthquake · 49 km W of this epicentre
- 6.6 1971 San Fernando Earthquake, California · 37 km WNW of this epicentre
- 5.9 The 1987 Whittier Narrows, California Earthquake · 23 km SSW of this epicentre
- 5.9 1km ENE of Granada Hills, California · 44 km W of this epicentre
- 5.8 10km SSW of Agua Dulce, CA · 37 km WNW 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 34.2573, -118.0115. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Los Angeles County, CA | 24 km (15 mi) | WSW | earthquakes near Los Angeles County |
| Orange County, CA | 68 km (42 mi) | SSE | earthquakes near Orange County |
| Ventura County, CA | 104 km (64 mi) | W | earthquakes near Ventura County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
32 earthquakes have been recorded within 50 km since this one.
- 1.6 1km SSW of Sylmar, CA
- 1.7 7km SSE of Littlerock, CA
- 1.6 8km SW of Lytle Creek, CA
- 1.9 4km SSW of San Dimas, CA
- 2.1 6km SSW of Pearblossom, CA
- 1.5 1km NNW of La Habra, CA
- 1.7 4km SSW of Pinon Hills, CA
- 2.3 3km S of Yorba Linda, CA
- 2.5 2km ESE of Granada Hills, CA
- 1.9 5km SSW of Pinon Hills, CA
- 1.6 4km W of South El Monte, CA
- 1.6 3km NNW of Brea, CA
- 1.6 9km SSE of Chino, CA
- 1.5 3km SW of La Mirada, CA
- 2.5 8km NNW of Rancho Cucamonga, 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.