QuakeIndex

Earthquake · reviewed by a seismologist

M 3.2ml

Earthquake near Ukiah, CA

Yes: an earthquake was likely felt in Ukiah in the last 24 hours. M 1.5, 5 km (3 mi) E of Ukiah, at 3:26 am PST on 12 November 2026 (11:26 UTC); the estimated shaking in Ukiah was intensity II (weak). Every earthquake near Ukiah

This page: a magnitude 3.2 earthquake was recorded 32 km (20 mi) west of Ukiah, CA, at 8:05 am PDT on 3 September 2019 (15:05 UTC), 5.5 km deep. 60 people have reported feeling it to USGS.

USGS: 18km ESE of Navarro Head, CA

8:05 am PDT, Sep 3, 2019 · · 5.5 km deep · released about 1.1 tons of TNT

10 km30 km60 km120 km N Mendocino County 35 kmLake County 72 kmSonoma County 88 kmGlenn County 114 kmColusa 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
8:05 am PDT on 3 September 2019 ()
Where
32 km (20 mi) west of Ukiah, CA · earthquakes near Ukiah
Magnitude
M 3.2 (ml)
Depth
5.5 km below the surface
Felt
60 reports · strongest reported intensity V
Nearest
Mendocino County, 35 km NNE
Nearest mapped fault
San Andreas fault, 15 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 2439 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 48 km (30 mi) from the epicentre. In Ukiah, 32 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: Boonville 23 km, intensity II · Ukiah 32 km, intensity II · Willits 36 km, intensity II · Brooktrails 38 km, intensity II · Fort Bragg 40 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 150,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 6,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,900× the energy of this one
  4. This earthquake M 3.2 about 1.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.3× 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 4.3 on 2019-04-29 — about 42 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 · 42 km E 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 39.1328, -123.5800. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 35 km (22 mi) NNE earthquakes near Mendocino County
Lake County, CA 72 km (45 mi) E earthquakes near Lake County
Sonoma County, CA 88 km (55 mi) SE earthquakes near Sonoma County
Glenn County, CA 114 km (71 mi) ENE earthquakes near Glenn County
Colusa County, CA 116 km (72 mi) E earthquakes near Colusa County
Napa County, CA 129 km (80 mi) ESE earthquakes near Napa County

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

Aftershocks so far

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

  1. 1.9 11km SSE of Talmage, CA
  2. 2.1 11km SSE of Talmage, CA
  3. 1.6 4km SE of Boonville, CA
  4. 1.6 2km E of Willits, CA
  5. 1.7 6km ENE of Redwood Valley, CA
  6. 1.6 23km SSW of Willits, CA
  7. 2.0 10km SSE of Talmage, CA
  8. 1.6 10km NNW of Redwood Valley, CA
  9. 1.6 15km ESE of Navarro Head, CA
  10. 2.5 6km ESE of Point Arena, CA
  11. 1.6 9km ENE of Brooktrails, CA
  12. 1.8 7km ESE of Redwood Valley, CA
  13. 1.7 2km WNW of Redwood Valley, CA
  14. 2.0 2km W of Redwood Valley, CA
  15. 1.8 2km WNW 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.