Earthquake · reviewed by a seismologist
M 2.4md
Earthquake near Chester, CA
No earthquake was likely felt in Chester in the 24 hours to 12:48 am PST (08:48 UTC). The last one was M 2.1, 17 km (11 mi) SE, at 8:09 am PDT on 29 October 2026, estimated intensity II (weak) in town. Every earthquake near Chester
This page: a magnitude 2.4 earthquake was recorded 15 km (9 mi) southeast of Chester, CA, at 4:39 am PST on 6 December 2019 (12:39 UTC), 4.2 km deep. 1 person has reported feeling it to USGS.
USGS: 2km ESE of Prattville, CA
- When
- 4:39 am PST on 6 December 2019 ()
- Where
- 15 km (9 mi) southeast of Chester, CA · earthquakes near Chester
- Magnitude
- M 2.4 (md)
- Depth
- 4.2 km below the surface
- Felt
- 1 report · strongest reported intensity II
- Nearest
- Plumas County, 35 km SE
- Nearest mapped fault
- Almanor fault, 5 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 2527 days ago
Earthquake alerts for Chester, CA
Get a notification in this browser when USGS records an earthquake near Chester, 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 20 km (12 mi) from the epicentre. In Chester, 15 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.
Likely felt in: Chester 15 km, intensity II · Westwood 16 km, intensity II · Greenville 17 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 100 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 150,000× the energy of this one
- Magna, Utah 2020 M 5.7 110,000× the energy of this one
- Around the size people start to feel M 3.0 9.4× the energy of this one
- This earthquake M 2.4 about 100 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
No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.
Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:
- 5.7 2 km NNE of Canyondam, California · 6 km E of this epicentre
- 5.5 15 km NE of Mineral, California · 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 40.2020, -121.1293. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Plumas County, CA | 35 km (22 mi) | SE | earthquakes near Plumas County |
| Lassen County, CA | 71 km (44 mi) | NE | earthquakes near Lassen County |
| Butte County, CA | 72 km (45 mi) | SW | earthquakes near Butte County |
| Sierra County, CA | 87 km (54 mi) | SE | earthquakes near Sierra County |
| Tehama County, CA | 94 km (58 mi) | W | earthquakes near Tehama County |
| Shasta County, CA | 99 km (62 mi) | NW | earthquakes near Shasta County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
58 earthquakes have been recorded within 50 km since this one.
- 1.5 1km WNW of Canyondam, CA
- 1.9 5km NE of Greenhorn, CA
- 2.5 4km NE of Greenhorn, CA
- 2.0 3km E of Prattville, CA
- 1.9 6km SE of Chester, CA
- 1.8 2km SSW of Canyondam, CA
- 1.7 7km NNW of Belden, CA
- 1.6 19km NW of Storrie, CA
- 1.6 4km SE of Canyondam, CA
- 1.9 5km ESE of Chester, CA
- 1.8 6km N of Almanor, CA
- 1.9 12km ENE of Mineral, CA
- 1.6 4km NE of Canyondam, CA
- 1.5 12km N of Mineral, CA
- 1.6 7km S of Mineral, 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.