QuakeIndex

Earthquake · reviewed by a seismologist

M 2.2md

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 2.2 earthquake was recorded 36 km (22 mi) west of Ukiah, CA, at 2:48 am PDT on 1 November 2017 (09:48 UTC), 6.6 km deep.

USGS: 8 km SSW of Comptche, California

2:48 am PDT, Nov 1, 2017 · · 6.6 km deep · released about 52 lb of TNT

10 km30 km60 km120 km N Mendocino County 31 kmLake County 76 kmSonoma County 96 kmGlenn County 114 kmColusa County 119 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
2:48 am PDT on 1 November 2017 ()
Where
36 km (22 mi) west of Ukiah, CA · earthquakes near Ukiah
Magnitude
M 2.2 (md)
Depth
6.6 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 31 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 3295 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 17 km (11 mi) from the epicentre. In Ukiah, 36 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.

How big was it?

This earthquake released about 52 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 290,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 200,000× the energy of this one
  3. Around the size people start to feel M 3.0 18× the energy of this one
  4. This earthquake M 2.2 about 52 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

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

  1. 5.2 6 km ESE of Talmage, California · 46 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 39.1918, -123.6230. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 31 km (19 mi) NNE earthquakes near Mendocino County
Lake County, CA 76 km (47 mi) E earthquakes near Lake County
Sonoma County, CA 96 km (59 mi) SE earthquakes near Sonoma County
Glenn County, CA 114 km (71 mi) ENE earthquakes near Glenn County
Colusa County, CA 119 km (74 mi) E earthquakes near Colusa County
Napa County, CA 136 km (84 mi) ESE earthquakes near Napa County

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

Aftershocks so far

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

  1. 1.6 2km N of Talmage, CA
  2. 1.7 8km W of Redwood Valley, CA
  3. 1.6 13km N of Brooktrails, CA
  4. 2.2 12km SSE of Talmage, CA
  5. 1.8 11km NNE of Redwood Valley, CA
  6. 1.8 18km WNW of Brooktrails, CA
  7. 1.5 13km WSW of Laytonville, CA
  8. 2.4 7km ESE of Point Arena, CA
  9. 1.5 15km SSW of Willits, CA
  10. 2.1 3km WSW of Navarro Head, CA
  11. 1.8 4km SE of Boonville, CA
  12. 2.1 3km SE of Redwood Valley, CA
  13. 1.6 2km SE of Redwood Valley, CA
  14. 2.2 15km SE of Boonville, CA
  15. 1.7 15km SSW 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.