QuakeIndex

Earthquake · reviewed by a seismologist

M 2.6md

Earthquake near Brooktrails, CA

No earthquake was likely felt in Brooktrails in the 24 hours to 6:31 am PST (14:31 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 2.6 earthquake was recorded 11 km (7 mi) north of Brooktrails, CA, at 8:27 pm PDT on 18 March 2024 (03:27 UTC), 8.8 km deep. 2 people have reported feeling it to USGS.

USGS: 11 km N of Brooktrails, CA

8:27 pm PDT, Mar 18, 2024 · · 8.8 km deep · released about 210 lb of TNT

Every earthquake near Brooktrails Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 14 kmLake County 72 kmGlenn County 83 kmColusa County 105 kmTehama County 116 kmSonoma County 119 km
Distance rings around the epicentre, with the nearest towns at their true direction and later quakes as coloured dots. Not a shaking map — see the USGS ShakeMap for that.
When
8:27 pm PDT on 18 March 2024 ()
Where
11 km (7 mi) north of Brooktrails, CA · earthquakes near Brooktrails
Magnitude
M 2.6 (md)
Depth
8.8 km below the surface
Felt
2 reports · strongest reported intensity II
Nearest
Mendocino County, 14 km SSW
Nearest mapped fault
Maacama fault, 5 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 899 days ago

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 21 km (13 mi) from the epicentre. In Brooktrails, 11 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 11 km, intensity II · Willits 15 km, intensity II · Laytonville 19 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 210 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 72,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 51,000× the energy of this one
  3. Around the size people start to feel M 3.0 4.6× the energy of this one
  4. This earthquake M 2.6 about 210 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 4.3 on 2019-04-29 — about 440 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 · 41 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 39.5438, -123.3642. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 14 km (9 mi) SSW earthquakes near Mendocino County
Lake County, CA 72 km (45 mi) SE earthquakes near Lake County
Glenn County, CA 83 km (51 mi) E earthquakes near Glenn County
Colusa County, CA 105 km (65 mi) ESE earthquakes near Colusa County
Tehama County, CA 116 km (72 mi) NE earthquakes near Tehama County
Sonoma County, CA 119 km (74 mi) SSE earthquakes near Sonoma County

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

Aftershocks so far

57 earthquakes have been recorded within 50 km since this one.

  1. 2.0 5 km WSW of Laytonville, CA
  2. 2.0 10 km of Lake Pillsbury, CA
  3. 1.5 11 km WNW of Laytonville, CA
  4. 1.7 4 km WSW of Laytonville, CA
  5. 1.6 4 km NNE of Lake Pillsbury, CA
  6. 1.5 5 km W of Laytonville, CA
  7. 2.1 5 km WSW of Laytonville, CA
  8. 3.6 5 km WSW of Laytonville, CA
  9. 2.0 5 km WSW of Laytonville, CA
  10. 1.6 5 km W of Laytonville, CA
  11. 2.1 5 km W of Laytonville, CA
  12. 4.3 5 km WSW of Laytonville, CA
  13. 2.3 10 km W of Alder Springs, CA
  14. 1.6 6 km ENE of Brooktrails, CA
  15. 1.6 11 km WNW of Laytonville, 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

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