QuakeIndex

Earthquake · automatic estimate, may change

M 3.4ml

Earthquake near Brooktrails, CA

USGS: 14 km N of Brooktrails, CA

7:48 pm PDT, Oct 9, 2026 · · 8.5 km deep · released about 2 tons of TNT

10 km30 km60 km120 km N Mendocino County 17 kmLake County 73 kmGlenn County 82 kmColusa County 105 kmTehama County 114 km
Distance rings around the epicentre, with the nearest towns at their true direction. Not a shaking map — see the USGS ShakeMap for that.
When
7:48 pm PDT on 9 October 2026 ()
Where
14 km (9 mi) N of Brooktrails, CA · earthquakes near Brooktrails
Magnitude
M 3.4 (ml)
Depth
8.5 km below the surface
Felt
9 reports · strongest reported intensity III
Nearest
Mendocino County, 17 km SSW
Nearest mapped fault
Maacama fault, 7 km from its surface trace — near is not the same as on
Status
Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS · we first saw it 1 hour ago

A magnitude 3.4 earthquake was recorded 14 km (9 mi) N of Brooktrails, CA, at 7:48 pm PDT on 9 October 2026 (02:48 UTC). 9 people have reported feeling it to USGS. This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 58 km (36 mi) from the epicentre. In Brooktrails, 14 km away, the estimate is intensity III (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: Laytonville, Willits, Covelo.

How big was it?

This earthquake released about 2 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 83,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 3,700× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,600× the energy of this one
  4. This earthquake M 3.4 about 2 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 4.3× more

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 5.6 on 2026-06-24 — about 1,800 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.9 9 km S of Leggett, California · 40 km NW 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 39.5688, -123.3555. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 17 km (11 mi) SSW earthquakes near Mendocino County
Lake County, CA 73 km (46 mi) SE earthquakes near Lake County
Glenn County, CA 82 km (51 mi) E earthquakes near Glenn County
Colusa County, CA 105 km (66 mi) ESE earthquakes near Colusa County
Tehama County, CA 114 km (71 mi) ENE earthquakes near Tehama County
Sonoma County, CA 122 km (76 mi) SSE earthquakes near Sonoma County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

No further earthquakes have been recorded within 50 km since this one.

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.

Revisions

USGS refines a solution as more stations report. Every change we have seen is listed here.

What changedFromToWhen
reported intensity2.93.1
felt reports79
felt reports67
felt reports56
felt reports25
reported intensitynot reported2.9
felt reportsnot reported2

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.