Earthquake · reviewed by a seismologist
M 1.6md
Earthquake near Willows, CA
No earthquake was likely felt in Willows in the 24 hours to 3:31 pm PST (23:31 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 1.6 earthquake was recorded 18 km (11 mi) east-southeast of Willows, CA, at 6:00 am PDT on 27 September 2019 (13:00 UTC), 23 km deep.
USGS: 18km ESE of Willows, CA
39 km (24 mi) SSW of Chico, CA · 108 km (67 mi) NNW of Sacramento, CA
- When
- 6:00 am PDT on 27 September 2019 ()
- Where
- 18 km (11 mi) east-southeast of Willows, CA · earthquakes near Willows
- Magnitude
- M 1.6 (md)
- Depth
- 23 km below the surface
- Felt
- no reports yet
- Nearest
- Colusa County, 35 km SSW
- Nearest mapped fault
- Great Valley thrust fault system, 24 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 2598 days ago
Earthquake alerts for Willows, CA
Get a notification in this browser when USGS records an earthquake near Willows, 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 Willows, 18 km away, the estimate is intensity I (not felt). 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: Maxwell, Colusa, Biggs, Gridley, Durham.
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
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:
- 5.7 The 1975 Oroville, California Earthquake · 40 km E of this epicentre
- 5.2 4 km E of Palermo, California · 45 km E of this epicentre
- 5.1 5 km ENE of Palermo, California · 46 km E 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 39.4418, -122.0122. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Colusa County, CA | 35 km (22 mi) | SSW | earthquakes near Colusa County |
| Glenn County, CA | 38 km (24 mi) | WNW | earthquakes near Glenn County |
| Butte County, CA | 43 km (27 mi) | NE | earthquakes near Butte County |
| Sutter County, CA | 52 km (33 mi) | SSE | earthquakes near Sutter County |
| Yuba County, CA | 61 km (38 mi) | ESE | earthquakes near Yuba County |
| Lake County, CA | 73 km (45 mi) | WSW | earthquakes near Lake County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
56 earthquakes have been recorded within 50 km since this one.
- 2.1 15km E of Willows, CA
- 2.3 4km SW of Hamilton City, CA
- 2.4 8km NNW of Hamilton City, CA
- 2.0 4km NE of Hamilton City, CA
- 1.8 5km NNE of Hamilton City, CA
- 1.7 10km S of Hamilton City, CA
- 2.0 10km NNW of Oroville, CA
- 2.5 4km NNE of Hamilton City, CA
- 2.5 5km NNE of Hamilton City, CA
- 2.6 5km NNE of Hamilton City, CA
- 1.8 6km SSE of Willows, CA
- 1.8 16km E of Willows, CA
- 1.8 5km NNE of Hamilton City, CA
- 1.7 11km W of Durham, CA
- 1.9 17km E of Willows, 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.