Earthquake · reviewed by a seismologist
M 1.7md
Earthquake near Brooktrails, CA
No earthquake was likely felt in Brooktrails in the 24 hours to 4:23 am PST (12:23 UTC). The last one was M 4.0, 38 km (23 mi) E, at 5:01 am PDT on 28 October 2026, estimated intensity III (weak) in town; 14 felt reports to USGS. Every earthquake near Brooktrails
This page: a magnitude 1.7 earthquake was recorded 9 km (5 mi) northeast of Brooktrails, CA, at 10:34 pm PDT on 19 October 2023 (05:34 UTC), 8.7 km deep.
USGS: 9 km NE of Brooktrails, CA
- When
- 10:34 pm PDT on 19 October 2023 ()
- Where
- 9 km (5 mi) northeast of Brooktrails, CA · earthquakes near Brooktrails
- Magnitude
- M 1.7 (md)
- Depth
- 8.7 km below the surface
- Felt
- no reports yet
- Nearest
- Mendocino County, 13 km WSW
- Nearest mapped fault
- Maacama fault, 8 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 1119 days ago
Earthquake alerts for Brooktrails, CA
Get a notification in this browser when USGS records an earthquake near Brooktrails, 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 Brooktrails, 9 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: Brooktrails 9 km, intensity II. Estimated for each town centre; each link is that town's own record.
How big was it?
This earthquake released about 10 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.
- Mineral, Virginia 2011 M 5.8 1,500,000× the energy of this one
- Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
- Around the size people start to feel M 3.0 95× the energy of this one
- This earthquake M 1.7 about 10 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 5.1 on 2016-08-10 — about 130,000 times the energy of this one.
Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:
- 5.9 9 km S of Leggett, California · 49 km NW of this epicentre
- 5.2 6 km ESE of Talmage, California · 45 km SSE 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 39.4878, -123.3032. Map © OpenStreetMap contributors.
Nearby places
| Place | Distance | Direction from the epicentre | |
|---|---|---|---|
| Mendocino County, CA | 13 km (8 mi) | WSW | earthquakes near Mendocino County |
| Lake County, CA | 64 km (40 mi) | SE | earthquakes near Lake County |
| Glenn County, CA | 78 km (49 mi) | E | earthquakes near Glenn County |
| Colusa County, CA | 98 km (61 mi) | ESE | earthquakes near Colusa County |
| Sonoma County, CA | 112 km (70 mi) | SSE | earthquakes near Sonoma County |
| Tehama County, CA | 116 km (72 mi) | NE | earthquakes near Tehama County |
Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.
Aftershocks so far
55 earthquakes have been recorded within 50 km since this one.
- 2.1 10 km NNW of Laytonville, CA
- 3.1 5 km NNE of Boonville, CA
- 1.8 14 km SSW of Laytonville, CA
- 2.1 6 km SSE of Redwood Valley, CA
- 1.6 10 km ESE of Willits, CA
- 1.6 10 km ESE of Rockport, CA
- 1.9 14 km WNW of Lake Pillsbury, CA
- 1.8 14 km WNW of Lake Pillsbury, CA
- 1.5 23 km SSW of Willits, CA
- 1.8 10 km NNW of Redwood Valley, CA
- 1.6 15 km WNW of Ukiah, CA
- 3.2 11 km NE of Redwood Valley, CA
- 1.5 13 km NE of Redwood Valley, CA
- 2.4 6 km ENE of Willits, CA
- 2.2 9 km NNW of Redwood Valley, 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.