Earthquake · reviewed by a seismologist
M 1.6md
Earthquake near Chester, CA
No earthquake was likely felt in Chester in the 24 hours to 4:27 am PST (12:27 UTC). The last one was M 2.1, 17 km (11 mi) SE, at 8:09 am PDT on 29 October 2026, estimated intensity II (weak) in town. Every earthquake near Chester
This page: a magnitude 1.6 earthquake was recorded 18 km (11 mi) northwest of Chester, CA, at 1:05 pm PDT on 30 July 2026 (20:05 UTC), 5.1 km deep.
USGS: 18 km ENE of Mineral, CA
84 km (52 mi) NNE of Chico, CA
- When
- 1:05 pm PDT on 30 July 2026 ()
- Where
- 18 km (11 mi) northwest of Chester, CA · earthquakes near Chester
- Magnitude
- M 1.6 (md)
- Depth
- 5.1 km below the surface
- Felt
- no reports yet
- Nearest
- Shasta County, 67 km WNW
- Nearest mapped fault
- Almanor fault, 11 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 93 days ago
Earthquake alerts for Chester, CA
Get a notification in this browser when USGS records an earthquake near Chester, 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, people at rest would likely notice it out to about 9 km (6 mi) from the epicentre. In Chester, 18 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.
How big was it?
This earthquake released about 6.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 2,300,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,600,000× the energy of this one
- Around the size people start to feel M 3.0 140× the energy of this one
- This earthquake M 1.6 about 6.6 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
The largest earthquake within 50 km since 2016 was M 5.5 on 2023-05-11 — about 760,000 times the energy of this one.
Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:
- 5.7 2 km NNE of Canyondam, California · 38 km SE of this epicentre
- 5.5 15 km NE of Mineral, California · 8 km WNW 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 40.4300, -121.3745. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Shasta County, CA | 67 km (42 mi) | WNW | earthquakes near Shasta County |
| Plumas County, CA | 67 km (42 mi) | SE | earthquakes near Plumas County |
| Lassen County, CA | 71 km (44 mi) | ENE | earthquakes near Lassen County |
| Tehama County, CA | 80 km (50 mi) | WSW | earthquakes near Tehama County |
| Butte County, CA | 87 km (54 mi) | SSW | earthquakes near Butte County |
| Sierra County, CA | 119 km (74 mi) | SE | earthquakes near Sierra County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
23 earthquakes have been recorded within 50 km since this one.
- 1.8 14 km NW of Belden, CA
- 2.1 3 km S of East Shore, CA
- 1.7 13 km SW of Chester, CA
- 2.1 2 km N of Canyondam, CA
- 2.3 10 km WNW of Caribou, CA
- 2.0 2 km NE of Almanor, CA
- 1.9 3 km NE of Almanor, CA
- 2.3 1 km NNE of Almanor, CA
- 1.9 14 km WSW of Almanor, CA
- 1.7 4 km N of Canyondam, CA
- 2.4 12 km WSW of Chester, CA
- 1.5 12 km WSW of Chester, CA
- 1.6 9 km ENE of Mineral, CA
- 1.7 9 km ENE of Shingletown, CA
- 2.0 3 km N of Canyondam, 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.