QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Redwood Valley, CA

No earthquake was likely felt in Redwood Valley in the 24 hours to 12:48 pm PST (20:48 UTC). The last one was M 1.5, 7 km (5 mi) SE, at 12:31 pm PST on 11 November 2026, estimated intensity II (weak) in town. Every earthquake near Redwood Valley

This page: a magnitude 1.7 earthquake was recorded 10 km (6 mi) north-northwest of Redwood Valley, CA, at 10:43 pm PDT on 20 August 2025 (05:43 UTC), 6.8 km deep.

USGS: 10 km NNW of Redwood Valley, CA

10:43 pm PDT, Aug 20, 2025 · · 6.8 km deep · released about 12 lb of TNT

Every earthquake near Redwood Valley Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 19 kmLake County 51 kmGlenn County 77 kmColusa County 89 kmSonoma County 96 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
10:43 pm PDT on 20 August 2025 ()
Where
10 km (6 mi) north-northwest of Redwood Valley, CA · earthquakes near Redwood Valley
Magnitude
M 1.7 (md)
Depth
6.8 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 19 km WNW
Nearest mapped fault
Maacama fault, 7 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 442 days ago

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 11 km (7 mi) from the epicentre. In Redwood Valley, 10 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.

Earthquakes near other towns within 30 km: Willits, Brooktrails, Ukiah, Talmage.

How big was it?

This earthquake released about 12 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.

  1. Mineral, Virginia 2011 M 5.8 1,200,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 870,000× the energy of this one
  3. Around the size people start to feel M 3.0 78× the energy of this one
  4. This earthquake M 1.7 about 12 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 110,000 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 · 29 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 39.3533, -123.2417. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 19 km (12 mi) WNW earthquakes near Mendocino County
Lake County, CA 51 km (32 mi) ESE earthquakes near Lake County
Glenn County, CA 77 km (48 mi) ENE earthquakes near Glenn County
Colusa County, CA 89 km (55 mi) ESE earthquakes near Colusa County
Sonoma County, CA 96 km (60 mi) SSE earthquakes near Sonoma County
Tehama County, CA 122 km (76 mi) NE earthquakes near Tehama 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.

  1. 1.6 12 km N of Upper Lake, CA
  2. 1.6 16 km ESE of Navarro Head, CA
  3. 2.5 14 km NNE of Lake Pillsbury, CA
  4. 1.8 20 km SSW of Willits, CA
  5. 1.9 16 km WNW of Lake Pillsbury, CA
  6. 1.7 14 km N of Brooktrails, CA
  7. 1.7 2 km SSE of Navarro Head, CA
  8. 2.2 16 km WNW of Lake Pillsbury, CA
  9. 1.6 20 km SSW of Willits, CA
  10. 2.5 12 km N of Brooktrails, CA
  11. 1.5 16 km WNW of Lake Pillsbury, CA
  12. 1.5 7 km NE of Willits, CA
  13. 1.5 10 km NNW of Redwood Valley, CA
  14. 1.6 14 km N of Lake Pillsbury, CA
  15. 1.6 10 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

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