QuakeIndex

Earthquake · reviewed by a seismologist

M 3.5mw

Earthquake near Redwood Valley, CA

Yes: an earthquake was likely felt in Redwood Valley in the last 24 hours. M 1.5, 7 km (5 mi) SE of Redwood Valley, at 12:31 pm PST on 11 November 2026 (20:31 UTC); the estimated shaking in Redwood Valley was intensity II (weak). Every earthquake near Redwood Valley

This page: a magnitude 3.5 earthquake was recorded in Redwood Valley, CA, at 4:30 am PST on 29 January 2020 (12:30 UTC), 6.4 km deep. 147 people have reported feeling it to USGS.

USGS: 2km W of Redwood Valley, CA

4:30 am PST, Jan 29, 2020 · · 6.4 km deep · released about 2.4 tons of TNT

10 km30 km60 km120 km N Mendocino County 26 kmLake County 45 kmGlenn County 80 kmColusa County 85 kmSonoma County 86 kmNapa County 115 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
4:30 am PST on 29 January 2020 ()
Where
in Redwood Valley, CA · earthquakes near Redwood Valley
Magnitude
M 3.5 (mw)
Depth
6.4 km below the surface
Felt
147 reports · strongest reported intensity IV
Measured shaking
intensity V (ShakeMap)
Nearest
Mendocino County, 26 km NW
Nearest mapped fault
Maacama fault, under 1 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 2268 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 61 km (38 mi) from the epicentre. 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: Ukiah 13 km, intensity III · Willits 20 km, intensity III · Brooktrails 24 km, intensity III · Upper Lake 29 km, intensity II · Boonville 31 km, intensity II · Lakeport 36 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 2.4 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.5 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 70,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 3,100× the energy of this one
  3. Magna, Utah 2020 M 5.7 2,200× the energy of this one
  4. This earthquake M 3.5 about 2.4 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 5.1× 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 5.1 on 2016-08-10 — about 270 times the energy of this one.

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

  1. 5.2 6 km ESE of Talmage, California · 20 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 39.2677, -123.2220. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 26 km (16 mi) NW earthquakes near Mendocino County
Lake County, CA 45 km (28 mi) ESE earthquakes near Lake County
Glenn County, CA 80 km (50 mi) ENE earthquakes near Glenn County
Colusa County, CA 85 km (53 mi) E earthquakes near Colusa County
Sonoma County, CA 86 km (54 mi) SSE earthquakes near Sonoma County
Napa County, CA 115 km (71 mi) SE earthquakes near Napa County

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

Aftershocks so far

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

  1. 2.0 1km WSW of Redwood Valley, CA
  2. 1.5 17km ESE of Boonville, CA
  3. 1.6 12km WNW of Redwood Valley, CA
  4. 1.8 2km W of Redwood Valley, CA
  5. 2.1 1km WSW of Redwood Valley, CA
  6. 2.1 2km SW of Redwood Valley, CA
  7. 1.9 1km W of Redwood Valley, CA
  8. 1.8 1km WSW of Redwood Valley, CA
  9. 1.9 1km WSW of Redwood Valley, CA
  10. 1.9 1km SW of Redwood Valley, CA
  11. 1.9 1km W of Redwood Valley, CA
  12. 3.6 1km SW of Redwood Valley, CA
  13. 2.3 1km WSW of Redwood Valley, CA
  14. 2.6 2km SW of Redwood Valley, CA
  15. 2.2 16km ESE of Boonville, 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.