QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

Earthquake near Willows, CA

No earthquake was likely felt in Willows in the 24 hours to 2:50 am PST (10:50 UTC). The last one was M 4.0, 65 km (40 mi) W, at 5:01 am PDT on 28 October 2026, estimated intensity II (weak) in town; 14 felt reports to USGS. Every earthquake near Willows

This page: a magnitude 2.4 earthquake was recorded 7 km (4 mi) west-northwest of Willows, CA, at 5:51 pm PDT on 6 May 2021 (00:51 UTC), 28 km deep. 3 people have reported feeling it to USGS.

USGS: 7km WNW of Willows, CA

46 km (29 mi) WSW of Chico, CA · 128 km (80 mi) NNW of Sacramento, CA

5:51 pm PDT, May 6, 2021 · · 28 km deep · released about 130 lb of TNT

10 km30 km60 km120 km N Glenn County 13 kmColusa County 40 kmButte County 59 kmLake County 63 kmTehama County 65 kmSutter County 74 kmYuba County 85 kmYolo County 101 kmMendocino County 101 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
5:51 pm PDT on 6 May 2021 ()
Where
7 km (4 mi) west-northwest of Willows, CA · earthquakes near Willows
Magnitude
M 2.4 (md)
Depth
28 km below the surface
Felt
3 reports · strongest reported intensity III
Nearest
Glenn County, 13 km WNW
Nearest mapped fault
Great Valley thrust fault system, 2 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 2015 days ago

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 Willows, 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: Orland, Maxwell.

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.

  1. Mineral, Virginia 2011 M 5.8 120,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 83,000× the energy of this one
  3. Around the size people start to feel M 3.0 7.4× the energy of this one
  4. 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 since 1900 lists no earthquake of M5 or more within 50 km.

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 39.5383, -122.2743. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Glenn County, CA 13 km (8 mi) WNW earthquakes near Glenn County
Colusa County, CA 40 km (25 mi) S earthquakes near Colusa County
Butte County, CA 59 km (37 mi) ENE earthquakes near Butte County
Lake County, CA 63 km (39 mi) SW earthquakes near Lake County
Tehama County, CA 65 km (41 mi) N earthquakes near Tehama County
Sutter County, CA 74 km (46 mi) SE earthquakes near Sutter County

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

Aftershocks so far

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

  1. 2.0 20km NE of Upper Lake, CA
  2. 1.8 21km NNE of Nice, CA
  3. 1.9 3km NW of Chico, CA
  4. 1.8 8km WSW of Alder Springs, CA
  5. 2.7 2km NW of Chico, CA
  6. 2.1 13km SSE of Willows, CA
  7. 2.6 12km S of Hamilton City, CA
  8. 2.7 5km N of Hamilton City, CA
  9. 2.2 15km SW of Orland, CA
  10. 2.1 10km W of Willows, CA
  11. 1.7 9km W of Williams, CA
  12. 3.7 10km WSW of Williams, CA
  13. 2.1 9km WSW of Williams, CA
  14. 2.0 11km NNW of Chico, CA
  15. 1.7 14km S of Hamilton City, 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.