QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

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 1.8 earthquake was recorded 3 km (2 mi) northwest of Redwood Valley, CA, at 6:02 am PDT on 16 August 2018 (13:02 UTC), 4.1 km deep.

USGS: 3km NW of Redwood Valley, CA

6:02 am PDT, Aug 16, 2018 · · 4.1 km deep · released about 16 lb of TNT

10 km30 km60 km120 km N Mendocino County 25 kmLake County 46 kmGlenn County 79 kmColusa County 86 kmSonoma County 88 kmNapa County 116 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
6:02 am PDT on 16 August 2018 ()
Where
3 km (2 mi) northwest of Redwood Valley, CA · earthquakes near Redwood Valley
Magnitude
M 1.8 (md)
Depth
4.1 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 25 km NW
Nearest mapped fault
Maacama fault, 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 3008 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 13 km (8 mi) from the epicentre. In Redwood Valley, 3 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: Ukiah, Talmage, Willits, Brooktrails, Upper Lake.

How big was it?

This earthquake released about 16 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 970,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 680,000× the energy of this one
  3. Around the size people start to feel M 3.0 61× the energy of this one
  4. This earthquake M 1.8 about 16 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 83,000 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 · 22 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 39.2837, -123.2230. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 25 km (16 mi) NW earthquakes near Mendocino County
Lake County, CA 46 km (28 mi) ESE earthquakes near Lake County
Glenn County, CA 79 km (49 mi) ENE earthquakes near Glenn County
Colusa County, CA 86 km (53 mi) E earthquakes near Colusa County
Sonoma County, CA 88 km (55 mi) SSE earthquakes near Sonoma County
Napa County, CA 116 km (72 mi) SE earthquakes near Napa County

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

Aftershocks so far

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

  1. 1.6 10km SSE of Laytonville, CA
  2. 1.9 7km NE of Brooktrails, CA
  3. 2.2 6km ESE of Willits, CA
  4. 3.8 6km ENE of Willits, CA
  5. 1.5 14km SSE of Talmage, CA
  6. 1.8 12km SE of Laytonville, CA
  7. 2.0 8km W of Upper Lake, CA
  8. 1.8 3km NW of Lake Pillsbury, CA
  9. 2.2 4km SW of Talmage, CA
  10. 2.1 6km SE of Redwood Valley, CA
  11. 1.9 8km SSE of Lake Pillsbury, CA
  12. 1.5 15km SW of Lakeport, CA
  13. 1.7 15km NE of Nice, CA
  14. 1.8 8km NNW of Redwood Valley, CA
  15. 2.1 14km NNE of Lake Pillsbury, 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.