QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Chico, CA

No earthquake was likely felt in Chico in the 24 hours to 4:15 am PST (12:15 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 2.1 earthquake was recorded 3 km (2 mi) west-northwest of Chico, CA, at 12:51 am PST on 19 February 2021 (08:51 UTC), 13 km deep.

USGS: 3km W of Chico, CA

in Chico, CA

12:51 am PST, Feb 19, 2021 · · 13 km deep · released about 40 lb of TNT

10 km30 km60 km120 km N Butte County 24 kmGlenn County 48 kmTehama County 53 kmYuba County 69 kmColusa County 70 kmSutter County 79 kmPlumas County 93 kmLake County 103 kmNevada County 106 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
12:51 am PST on 19 February 2021 ()
Where
3 km (2 mi) west-northwest of Chico, CA · earthquakes near Chico
Magnitude
M 2.1 (md)
Depth
13 km below the surface
Felt
no reports yet
Nearest
Butte County, 24 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2092 days ago

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 11 km (7 mi) from the epicentre. In Chico, 3 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: Chico 3 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 40 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 380,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 270,000× the energy of this one
  3. Around the size people start to feel M 3.0 24× the energy of this one
  4. This earthquake M 2.1 about 40 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 3 earthquakes of M5 or more within 50 km:

  1. 5.7 The 1975 Oroville, California Earthquake · 44 km SE of this epicentre
  2. 5.2 4 km E of Palermo, California · 47 km SE of this epicentre
  3. 5.1 5 km ENE of Palermo, California · 46 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 39.7395, -121.8668. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Butte County, CA 24 km (15 mi) ESE earthquakes near Butte County
Glenn County, CA 48 km (30 mi) WSW earthquakes near Glenn County
Tehama County, CA 53 km (33 mi) NW earthquakes near Tehama County
Yuba County, CA 69 km (43 mi) SE earthquakes near Yuba County
Colusa County, CA 70 km (44 mi) SSW earthquakes near Colusa County
Sutter County, CA 79 km (49 mi) S earthquakes near Sutter County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

49 earthquakes have been recorded within 50 km since this one.

  1. 2.9 6 km W of Hamilton City, CA
  2. 2.2 7 km ENE of Hamilton City, CA
  3. 2.5 28 km SSW of Mineral, CA
  4. 2.4 18 km E of Willows, CA
  5. 2.6 15 km ENE of Willows, CA
  6. 2.1 18km E of Willows, CA
  7. 2.2 18km E of Willows, CA
  8. 2.1 8km WSW of Durham, CA
  9. 2.3 14km S of Hamilton City, CA
  10. 1.9 3km NW of Chico, CA
  11. 2.1 10km N of Oroville, CA
  12. 2.0 5km SSE of Oroville East, CA
  13. 2.7 2km NW of Chico, CA
  14. 2.1 13km SSE of Willows, CA
  15. 4.2 5km S of Oroville East, 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

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.