QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

Earthquake near Ukiah, CA

Yes: an earthquake was likely felt in Ukiah in the last 24 hours. M 1.5, 10 km (6 mi) NE of Ukiah, at 12:31 pm PST on 11 November 2026 (20:31 UTC); the estimated shaking in Ukiah was intensity II (weak). Every earthquake near Ukiah

This page: a magnitude 2.9 earthquake was recorded 16 km (10 mi) west of Ukiah, CA, at 5:06 pm PST on 30 November 2020 (01:06 UTC), 4.6 km deep. 51 people have reported feeling it to USGS.

USGS: 16km W of Ukiah, CA

99 km (62 mi) NW of Santa Rosa, CA

5:06 pm PST, Nov 30, 2020 · · 4.6 km deep · released about 720 lb of TNT

10 km30 km60 km120 km N Mendocino County 30 kmLake County 56 kmSonoma County 81 kmGlenn County 98 kmColusa County 99 kmNapa County 118 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
5:06 pm PST on 30 November 2020 ()
Where
16 km (10 mi) west of Ukiah, CA · earthquakes near Ukiah
Magnitude
M 2.9 (md)
Depth
4.6 km below the surface
Felt
51 reports · strongest reported intensity IV
Nearest
Mendocino County, 30 km N
Nearest mapped fault
Maacama fault, 17 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 1996 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 33 km (21 mi) from the epicentre. In Ukiah, 16 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.

Likely felt in: Ukiah 16 km, intensity III · Boonville 17 km, intensity II · Willits 28 km, intensity II · Brooktrails 31 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 720 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 21,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 15,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.3× the energy of this one
  4. This earthquake M 2.9 about 720 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 130 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 · 26 km ESE 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 39.1627, -123.3905. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 30 km (19 mi) N earthquakes near Mendocino County
Lake County, CA 56 km (35 mi) E earthquakes near Lake County
Sonoma County, CA 81 km (51 mi) SSE earthquakes near Sonoma County
Glenn County, CA 98 km (61 mi) ENE earthquakes near Glenn County
Colusa County, CA 99 km (62 mi) E earthquakes near Colusa County
Napa County, CA 118 km (73 mi) SE earthquakes near Napa County

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

Aftershocks so far

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

  1. 2.2 10km NNW of Redwood Valley, CA
  2. 1.6 14km ESE of Redwood Valley, CA
  3. 2.5 9km ESE of Redwood Valley, CA
  4. 1.6 9km E of Redwood Valley, CA
  5. 1.5 5km NNW of Redwood Valley, CA
  6. 2.8 15km W of Lakeport, CA
  7. 1.6 14km W of Lakeport, CA
  8. 2.4 14km W of Lakeport, CA
  9. 1.8 13km NNE of Brooktrails, CA
  10. 2.2 14km W of Lakeport, CA
  11. 1.9 5km S of Boonville, CA
  12. 2.0 12km SE of Laytonville, CA
  13. 1.7 4km S of Redwood Valley, CA
  14. 1.8 10km ESE of Willits, CA
  15. 1.7 10km SE of Willits, 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.