Earthquake · reviewed by a seismologist
M 3.1ml
Earthquake near Topanga, CA
No earthquake was likely felt in Topanga in the 24 hours to 3:12 am PST (11:12 UTC). The last one was M 2.3, 18 km (11 mi) N, at 9:45 am PST on 7 November 2026, estimated intensity II (weak) in town; 26 felt reports to USGS. Every earthquake near Topanga
This page: a magnitude 3.1 earthquake was recorded 6 km (4 mi) west of Topanga, CA, at 12:44 am PST on 8 December 2017 (08:44 UTC), 15 km deep. 572 people have reported feeling it to USGS.
USGS: 6km W of Topanga, CA
25 km (16 mi) WNW of Los Angeles, CA · 18 km (11 mi) WNW of Santa Monica, CA
- When
- 12:44 am PST on 8 December 2017 ()
- Where
- 6 km (4 mi) west of Topanga, CA · earthquakes near Topanga
- Magnitude
- M 3.1 (ml)
- Depth
- 15 km below the surface
- Felt
- 572 reports · strongest reported intensity IV
- Measured shaking
- intensity IV (ShakeMap)
- Nearest
- Los Angeles County, 39 km ENE
- Nearest mapped fault
- Malibu Coast fault, 6 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 3179 days ago
Earthquake alerts for Topanga, 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 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 41 km (25 mi) from the epicentre. In Topanga, 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: Agoura 8 km, intensity III · Thousand Oaks 17 km, intensity II · Santa Monica 19 km, intensity II · Simi Valley 22 km, intensity II · Moorpark 29 km, intensity II · Inglewood 33 km, intensity II · Manhattan Beach 34 km, intensity II · Burbank 35 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 1,500 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 6.7 230,000× the energy of this one
- Mineral, Virginia 2011 M 5.8 10,000× the energy of this one
- Magna, Utah 2020 M 5.7 7,200× the energy of this one
- This earthquake M 3.1 about 1,500 lb of TNT
- Around the size people start to feel M 3.0 this one released 1.6× 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
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 20 earthquakes of M5 or more within 50 km; the five largest:
- 6.7 Northridge, California, earthquake · 18 km NE of this epicentre
- 6.6 1971 San Fernando Earthquake, California · 45 km NE of this epicentre
- 5.9 1km ENE of Granada Hills, California · 26 km NE of this epicentre
- 5.8 10km SSW of Agua Dulce, CA · 45 km NE of this epicentre
- 5.8 10km SSW of Agua Dulce, CA · 45 km NE 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 34.0952, -118.6710. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Los Angeles County, CA | 39 km (24 mi) | ENE | earthquakes near Los Angeles County |
| Ventura County, CA | 52 km (32 mi) | NW | earthquakes near Ventura County |
| Orange County, CA | 95 km (59 mi) | ESE | earthquakes near Orange County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
50 earthquakes have been recorded within 50 km since this one.
- 1.7 8km S of Malibu Beach, CA
- 1.7 11km N of Piru, CA
- 2.4 16km SW of Malibu, CA
- 1.9 4km WSW of Compton, CA
- 1.8 2km NE of Silver Lake, CA
- 1.7 18km SSE of Malibu, CA
- 1.5 6km NNE of Granada Hills, CA
- 2.5 3km N of Carson, CA
- 1.7 12km S of Malibu Beach, CA
- 1.5 2km WSW of East Los Angeles, CA
- 1.7 6km ESE of Port Hueneme, CA
- 1.7 3km WSW of Culver City, CA
- 1.6 3km NW of Inglewood, CA
- 1.6 2km WNW of Inglewood, CA
- 1.7 7km NNW 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.