QuakeIndex

Earthquake · automatic estimate, may change

M 1.9md

Earthquake near Ukiah, CA

Yes: an earthquake was likely felt in Ukiah in the last 24 hours. M 2.4, 19 km (12 mi) N of Ukiah, at 3:48 am PDT on 20 October 2026 (10:48 UTC); the estimated shaking in Ukiah was intensity II (weak). Every earthquake near Ukiah

This page: a magnitude 1.9 earthquake was recorded 43 km (27 mi) north-northeast of Ukiah, CA, at 2:50 pm PDT on 17 October 2026 (21:50 UTC), 10 km deep. The magnitude and location are an automatic first estimate and may change.

USGS: 8 km N of Lake Pillsbury, CA

2:50 pm PDT, Oct 17, 2026 · · 10 km deep · released about 22 lb of TNT

10 km30 km60 km120 km N Mendocino County 43 kmLake County 45 kmGlenn County 49 kmColusa County 69 kmTehama County 94 kmSonoma County 106 kmButte County 117 kmSutter 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
2:50 pm PDT on 17 October 2026 ()
Where
43 km (27 mi) north-northeast of Ukiah, CA · earthquakes near Ukiah
Magnitude
M 1.9 (md)
Depth
10 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 43 km W
Nearest mapped fault
Bartlett Springs fault system, 2 km from its surface trace — near is not the same as on
Status
Automatic — a machine’s first estimate, which may change

USGS · last changed by USGS · we first saw it 3 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 11 km (7 mi) from the epicentre. In Ukiah, 43 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 22 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 680,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 480,000× the energy of this one
  3. Around the size people start to feel M 3.0 43× the energy of this one
  4. This earthquake M 1.9 about 22 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 5.6 on 2026-06-24 — about 330,000 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 · 42 km SSW 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 39.4775, -122.9457. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 43 km (27 mi) W earthquakes near Mendocino County
Lake County, CA 45 km (28 mi) SSE earthquakes near Lake County
Glenn County, CA 49 km (30 mi) ENE earthquakes near Glenn County
Colusa County, CA 69 km (43 mi) ESE earthquakes near Colusa County
Tehama County, CA 94 km (59 mi) NE earthquakes near Tehama County
Sonoma County, CA 106 km (66 mi) S earthquakes near Sonoma County

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

Aftershocks so far

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

  1. 2.4 6 km N of Redwood Valley, CA
  2. 1.8 14 km NNE of Brooktrails, 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.