QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

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 1.9 earthquake was recorded 42 km (26 mi) east-northeast of Ukiah, CA, at 11:25 pm PDT on 11 August 2016 (06:25 UTC), 16 km deep.

USGS: 20 km WSW of Stonyford, California

11:25 pm PDT, Aug 11, 2016 · · 16 km deep · released about 21 lb of TNT

10 km30 km60 km120 km N Lake County 26 kmGlenn County 44 kmColusa County 50 kmMendocino County 58 kmSonoma County 91 kmSutter County 99 kmTehama County 99 kmNapa County 100 kmYolo County 105 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
11:25 pm PDT on 11 August 2016 ()
Where
42 km (26 mi) east-northeast of Ukiah, CA · earthquakes near Ukiah
Magnitude
M 1.9 (md)
Depth
16 km below the surface
Felt
no reports yet
Nearest
Lake County, 26 km S
Nearest mapped fault
Bartlett Springs fault system, 6 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 3561 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

At this magnitude and depth it was probably too small to be felt, even directly above it. In Ukiah, 42 km away, the estimate is intensity I (not felt). 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.

Earthquakes near other towns within 30 km: Upper Lake, Nice, North Lakeport.

How big was it?

This earthquake released about 21 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 5.8 710,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 500,000× the energy of this one
  3. Around the size people start to feel M 3.0 45× the energy of this one
  4. This earthquake M 1.9 about 21 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 5.1 on 2016-08-10 — about 61,000 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 · 37 km SW 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 39.3383, -122.7813. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 26 km (16 mi) S earthquakes near Lake County
Glenn County, CA 44 km (27 mi) NE earthquakes near Glenn County
Colusa County, CA 50 km (31 mi) ESE earthquakes near Colusa County
Mendocino County, CA 58 km (36 mi) W earthquakes near Mendocino County
Sonoma County, CA 91 km (57 mi) S earthquakes near Sonoma County
Sutter County, CA 99 km (61 mi) ESE earthquakes near Sutter County

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

Aftershocks so far

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

  1. 2.2 20 km NNE of Upper Lake, California
  2. 2.1 18 km NNE of Upper Lake, California
  3. 2.0 7 km E of Clearlake Oaks, California
  4. 2.0 20 km NNE of Upper Lake, California
  5. 1.9 2 km E of Willits, California
  6. 1.6 5 km E of Redwood Valley, California
  7. 1.7 29 km SE of Covelo, California
  8. 1.8 28 km SE of Covelo, California
  9. 1.7 28 km SE of Covelo, California
  10. 1.7 19 km NNE of Upper Lake, California
  11. 1.7 19 km NE of Upper Lake, California
  12. 1.8 21 km NNE of Upper Lake, California
  13. 2.3 19 km NE of Upper Lake, California
  14. 1.7 19 km NE of Upper Lake, California
  15. 1.6 29 km NE of Potter Valley, California

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.