Earthquake · reviewed by a seismologist
M 2.5md
Earthquake near Chico, CA
No earthquake was likely felt in Chico in the 24 hours to 4:47 am PST (12:47 UTC). The last one was M 4.4, 120 km (75 mi) W, at 6:14 pm PDT on 10 July 2026, estimated intensity II (weak) in town; 66 felt reports to USGS. Every earthquake near Chico
This page: a magnitude 2.5 earthquake was recorded 7 km (4 mi) northwest of Chico, CA, at 5:27 am PDT on 19 September 2021 (12:27 UTC), 29 km deep.
USGS: 6km NW of Chico, CA
7 km (4 mi) WNW of Chico, CA
- When
- 5:27 am PDT on 19 September 2021 ()
- Where
- 7 km (4 mi) northwest of Chico, CA · earthquakes near Chico
- Magnitude
- M 2.5 (md)
- Depth
- 29 km below the surface
- Felt
- no reports yet
- Nearest
- Butte County, 28 km ESE
- Status
- Reviewed by a seismologist
USGS · last changed by USGS · we first saw it 1805 days ago
Earthquake alerts for Chico, 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 it was probably too small to be felt, even directly above it. In Chico, 7 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: Hamilton City, Durham, Forest Ranch, Paradise, Orland, Magalia.
How big was it?
This earthquake released about 150 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 100,000× the energy of this one
- Magna, Utah 2020 M 5.7 72,000× the energy of this one
- Around the size people start to feel M 3.0 6.5× the energy of this one
- This earthquake M 2.5 about 150 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 one earthquake of M5 or more within 50 km:
- 5.7 The 1975 Oroville, California Earthquake · 49 km SE 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 39.7792, -121.8905. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Butte County, CA | 28 km (17 mi) | ESE | earthquakes near Butte County |
| Glenn County, CA | 48 km (30 mi) | WSW | earthquakes near Glenn County |
| Tehama County, CA | 48 km (30 mi) | NW | earthquakes near Tehama County |
| Colusa County, CA | 73 km (45 mi) | SSW | earthquakes near Colusa County |
| Yuba County, CA | 73 km (46 mi) | SE | earthquakes near Yuba County |
| Sutter County, CA | 84 km (52 mi) | S | earthquakes near Sutter County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
44 earthquakes have been recorded within 50 km since this one.
- 2.7 12 km E of Red Bluff, CA
- 1.7 30 km SW of Mineral, CA
- 3.1 14 km NNE of Maxwell, CA
- 2.3 14 km NNE of Maxwell, CA
- 2.1 17 km ESE of Willows, CA
- 2.1 6 km W of Magalia, CA
- 2.3 7 km WNW of Hamilton City, CA
- 2.4 27 km SW of Mineral, CA
- 2.5 8 km E of Orland, CA
- 2.7 17 km ESE of Willows, CA
- 2.5 17 km ESE of Willows, CA
- 2.0 24 km NNE of Forest Ranch, CA
- 2.7 10 km ESE of Red Bluff, CA
- 2.2 13 km NW of Willows, CA
- 2.5 17 km E of Willows, 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.