Earthquake · reviewed by a seismologist
M 1.8md
Earthquake near Hamilton City, CA
No earthquake was likely felt in Hamilton City in the 24 hours to 4:41 am PST (12:41 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 1.8 earthquake was recorded 15 km (9 mi) south-southwest of Hamilton City, CA, at 3:19 am PDT on 8 June 2021 (10:19 UTC), 20 km deep.
USGS: 15km SSW of Hamilton City, CA
26 km (16 mi) SW of Chico, CA · 127 km (79 mi) NNW of Sacramento, CA
- When
- 3:19 am PDT on 8 June 2021 ()
- Where
- 15 km (9 mi) south-southwest of Hamilton City, CA · earthquakes near Hamilton City
- Magnitude
- M 1.8 (md)
- Depth
- 20 km below the surface
- Felt
- no reports yet
- Nearest
- Glenn County, 29 km W
- Nearest mapped fault
- Great Valley thrust fault system, 20 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 1983 days ago
Earthquake alerts for Hamilton City, CA
Get a notification in this browser when USGS records an earthquake near Hamilton City, CA. No account or email needed.
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 Hamilton City, 15 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: Willows, Orland, Durham, Chico.
How big was it?
This earthquake released about 17 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 870,000× the energy of this one
- Magna, Utah 2020 M 5.7 620,000× the energy of this one
- Around the size people start to feel M 3.0 55× the energy of this one
- This earthquake M 1.8 about 17 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 ESE 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 39.6170, -122.0610. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Glenn County, CA | 29 km (18 mi) | W | earthquakes near Glenn County |
| Butte County, CA | 40 km (25 mi) | E | earthquakes near Butte County |
| Colusa County, CA | 51 km (32 mi) | SSW | earthquakes near Colusa County |
| Tehama County, CA | 58 km (36 mi) | NNW | earthquakes near Tehama County |
| Sutter County, CA | 72 km (44 mi) | SSE | earthquakes near Sutter County |
| Yuba County, CA | 73 km (45 mi) | ESE | earthquakes near Yuba County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
59 earthquakes have been recorded within 50 km since this one.
- 2.2 5 km WNW of Magalia, CA
- 1.8 19 km ESE of Willows, CA
- 2.7 14 km E of Willows, CA
- 2.1 15 km ESE of Willows, CA
- 2.2 5 km ESE of Hamilton City, CA
- 2.7 7 km NNE of Hamilton City, CA
- 2.4 6 km NNE of Hamilton City, CA
- 2.2 6 km NNE of Hamilton City, CA
- 2.3 9 km E of Los Molinos, 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
- 2.5 8 km E of Orland, 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.