QuakeIndex

Earthquake · reviewed by a seismologist

M 2.4md

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 2.4 earthquake was recorded 46 km (29 mi) west of Ukiah, CA, at 5:14 am PDT on 6 April 2023 (12:14 UTC), less than 1 km deep. 2 people have reported feeling it to USGS.

USGS: 4km SSE of Navarro Head, CA

5:14 am PDT, Apr 6, 2023 · · -0.2 km deep · released about 130 lb of TNT

10 km30 km60 km120 km N Mendocino County 39 kmLake County 86 kmSonoma County 100 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
5:14 am PDT on 6 April 2023 ()
Where
46 km (29 mi) west of Ukiah, CA · earthquakes near Ukiah
Magnitude
M 2.4 (md)
Depth
-0.2 km below the surface
Felt
2 reports · strongest reported intensity III
Nearest
Mendocino County, 39 km NE
Nearest mapped fault
San Andreas fault, 4 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 1315 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 21 km (13 mi) from the epicentre. In Ukiah, 46 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 130 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.4 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 110,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 80,000× the energy of this one
  3. Around the size people start to feel M 3.0 7.2× the energy of this one
  4. This earthquake M 2.4 about 130 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 680 times the energy of this one.

Before 2016, the USGS record since 1900 lists no earthquake of M5 or more within 50 km.

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 39.1633, -123.7417. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 39 km (25 mi) NE earthquakes near Mendocino County
Lake County, CA 86 km (54 mi) E earthquakes near Lake County
Sonoma County, CA 100 km (62 mi) SE earthquakes near Sonoma County
Glenn County, CA 125 km (78 mi) ENE earthquakes near Glenn County

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

Aftershocks so far

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

  1. 1.9 2 km NW of Redwood Valley, CA
  2. 1.5 8 km SE of Willits, CA
  3. 2.0 14 km WNW of Boonville, CA
  4. 1.9 6 km SSE of Point Arena, CA
  5. 1.9 1 km NNW of Redwood Valley, CA
  6. 1.9 16 km NNE of Point Arena, CA
  7. 1.6 6 km NE of Willits, CA
  8. 2.1 9 km NNW of Redwood Valley, CA
  9. 1.6 15 km ENE of Point Arena, CA
  10. 1.8 23 km E of Navarro Head, CA
  11. 2.1 5 km ESE of Willits, CA
  12. 1.8 16 km NW of Brooktrails, CA
  13. 1.6 9 km ESE of Willits, CA
  14. 1.5 8km SE of Willits, CA
  15. 1.8 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.