QuakeIndex

Earthquake · reviewed by a seismologist

M 2.3md

Earthquake near Hamilton City, CA

No earthquake was likely felt in Hamilton City in the 24 hours to 3:26 pm PST (23:26 UTC). The last one was M 4.0, 85 km (53 mi) WSW, at 5:01 am PDT on 28 October 2026, estimated intensity II (weak) in town; 14 felt reports to USGS. Every earthquake near Hamilton City

This page: a magnitude 2.3 earthquake was recorded 5 km (3 mi) north-northeast of Hamilton City, CA, at 11:18 am PDT on 4 July 2020 (18:18 UTC), 17 km deep.

USGS: 5km NNE of Hamilton City, CA

15 km (9 mi) W of Chico, CA

11:18 am PDT, Jul 4, 2020 · · 17 km deep · released about 88 lb of TNT

10 km30 km60 km120 km N Butte County 35 kmGlenn County 41 kmTehama County 44 kmColusa County 71 kmYuba County 79 kmSutter County 86 kmLake County 99 kmPlumas County 102 kmShasta County 109 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
11:18 am PDT on 4 July 2020 ()
Where
5 km (3 mi) north-northeast of Hamilton City, CA · earthquakes near Hamilton City
Magnitude
M 2.3 (md)
Depth
17 km below the surface
Felt
no reports yet
Nearest
Butte County, 35 km ESE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2319 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 9 km (6 mi) from the epicentre. In Hamilton City, 5 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: Hamilton City 5 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 88 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.3 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 170,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 120,000× the energy of this one
  3. Around the size people start to feel M 3.0 11× the energy of this one
  4. This earthquake M 2.3 about 88 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 39.7818, -121.9863. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Butte County, CA 35 km (22 mi) ESE earthquakes near Butte County
Glenn County, CA 41 km (25 mi) WSW earthquakes near Glenn County
Tehama County, CA 44 km (27 mi) NNW earthquakes near Tehama County
Colusa County, CA 71 km (44 mi) SSW earthquakes near Colusa County
Yuba County, CA 79 km (49 mi) SE earthquakes near Yuba County
Sutter County, CA 86 km (54 mi) SSE earthquakes near Sutter 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. 2.9 6km NNE of Hamilton City, CA
  2. 2.5 6km NW of Chico, CA
  3. 2.5 5km NNE of Hamilton City, CA
  4. 1.8 4km NNE of Hamilton City, CA
  5. 2.0 9km N of Oroville, CA
  6. 1.9 14km S of Hamilton City, CA
  7. 2.6 15km E of Willows, CA
  8. 2.6 16km E of Willows, CA
  9. 2.3 16km E of Willows, CA
  10. 2.1 6km N of Hamilton City, CA
  11. 1.8 15km ENE of Willows, CA
  12. 1.8 5km W of Paradise, CA
  13. 1.6 9km N of Biggs, CA
  14. 2.2 15km E of Willows, CA
  15. 1.8 15km SSW 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.