Earthquake · reviewed by a seismologist
M 2.4md
Earthquake near Challenge-Brownsville, CA
No earthquake was likely felt in Challenge-Brownsville in the 24 hours to 9:05 pm PST (05:05 UTC). The last one was M 2.0, 6 km (4 mi) E, at 11:19 pm PDT on 31 August 2026, estimated intensity II (weak) in town. Every earthquake near Challenge-Brownsville
This page: a magnitude 2.4 earthquake was recorded 6 km (4 mi) south-southeast of Challenge-Brownsville, CA, at 10:04 pm PST on 9 November 2020 (06:04 UTC), 11 km deep. 290 people have reported feeling it to USGS.
USGS: 6km SSE of Challenge-Brownsville, CA
96 km (60 mi) NNE of Sacramento, CA · 47 km (29 mi) NE of Yuba City, CA
- When
- 10:04 pm PST on 9 November 2020 ()
- Where
- 6 km (4 mi) south-southeast of Challenge-Brownsville, CA · earthquakes near Challenge-Brownsville
- Magnitude
- M 2.4 (md)
- Depth
- 11 km below the surface
- Felt
- 290 reports · strongest reported intensity III
- Nearest
- Yuba County, 18 km SSW
- Nearest mapped fault
- Foothills fault system, 15 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 2119 days ago
Earthquake alerts for Challenge-Brownsville, 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 18 km (11 mi) from the epicentre. In Challenge-Brownsville, 6 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: Loma Rica, Lake Wildwood, Oroville East, Penn Valley, Palermo, Nevada City.
How big was it?
This earthquake released about 130 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 5.8 110,000× the energy of this one
- Magna, Utah 2020 M 5.7 80,000× the energy of this one
- Around the size people start to feel M 3.0 7.2× the energy of this one
- This earthquake M 2.4 about 130 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 5 earthquakes of M5 or more within 50 km:
- 5.9 West of Downieville, California · 23 km ENE of this epicentre
- 5.7 The 1975 Oroville, California Earthquake · 26 km W of this epicentre
- 5.2 4 km E of Palermo, California · 21 km W of this epicentre
- 5.1 5 km ENE of Palermo, California · 21 km W of this epicentre
- 5.0 Nevada County, California · 30 km E 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 39.4150, -121.2433. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Yuba County, CA | 18 km (11 mi) | SSW | earthquakes near Yuba County |
| Butte County, CA | 42 km (26 mi) | NW | earthquakes near Butte County |
| Nevada County, CA | 43 km (26 mi) | ESE | earthquakes near Nevada County |
| Sutter County, CA | 58 km (36 mi) | SW | earthquakes near Sutter County |
| Placer County, CA | 60 km (37 mi) | SE | earthquakes near Placer County |
| Sierra County, CA | 64 km (40 mi) | ENE | earthquakes near Sierra County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
22 earthquakes have been recorded within 50 km since this one.
- 2.0 6 km E of Challenge-Brownsville, CA
- 2.1 8 km WNW of La Porte, CA
- 2.1 7 km ESE of Challenge-Brownsville, CA
- 2.0 19 km S of Johnsville, CA
- 1.9 5 km WSW of Concow, CA
- 1.8 8 km NNE of Oroville East, CA
- 1.7 8 km NNE of Oroville East, CA
- 2.1 12 km W of La Porte, CA
- 1.6 Northern California
- 2.1 10km N of Oroville, CA
- 2.0 5km SSE of Oroville East, CA
- 2.3 10km WNW of Little Grass Valley, CA
- 4.2 5km S of Oroville East, CA
- 2.2 9km E of Little Grass Valley, CA
- 1.8 10km N of Oroville, 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.