QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

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 1.6 earthquake was recorded 26 km (16 mi) northeast of Ukiah, CA, at 12:03 am PST on 9 November 2019 (08:03 UTC), 7.5 km deep.

USGS: 10km SW of Lake Pillsbury, CA

12:03 am PST, Nov 9, 2019 · · 7.5 km deep · released about 7.6 lb of TNT

10 km30 km60 km120 km N Lake County 35 kmMendocino County 38 kmGlenn County 61 kmColusa County 70 kmSonoma County 91 kmNapa County 110 kmTehama County 111 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
12:03 am PST on 9 November 2019 ()
Where
26 km (16 mi) northeast of Ukiah, CA · earthquakes near Ukiah
Magnitude
M 1.6 (md)
Depth
7.5 km below the surface
Felt
no reports yet
Nearest
Lake County, 35 km SE
Nearest mapped fault
Bartlett Springs fault system, 7 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 2554 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 8 km (5 mi) from the epicentre. In Ukiah, 26 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: Redwood Valley, Upper Lake, Talmage, Nice, North Lakeport, Willits.

How big was it?

This earthquake released about 7.6 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,400,000× the energy of this one
  3. Around the size people start to feel M 3.0 130× the energy of this one
  4. This earthquake M 1.6 about 7.6 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 170,000 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 · 25 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 39.3358, -123.0210. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 35 km (22 mi) SE earthquakes near Lake County
Mendocino County, CA 38 km (23 mi) WNW earthquakes near Mendocino County
Glenn County, CA 61 km (38 mi) ENE earthquakes near Glenn County
Colusa County, CA 70 km (43 mi) ESE earthquakes near Colusa County
Sonoma County, CA 91 km (56 mi) S earthquakes near Sonoma County
Napa County, CA 110 km (68 mi) SSE 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. 1.8 1km WSW of Redwood Valley, CA
  2. 1.9 1km WSW of Redwood Valley, CA
  3. 1.9 1km SW of Redwood Valley, CA
  4. 1.9 1km W of Redwood Valley, CA
  5. 3.6 1km SW of Redwood Valley, CA
  6. 2.3 1km WSW of Redwood Valley, CA
  7. 2.6 2km SW of Redwood Valley, CA
  8. 2.2 16km ESE of Boonville, CA
  9. 1.5 16km N of Lake Pillsbury, CA
  10. 2.1 11km NNE of Talmage, CA
  11. 2.1 4km NW of Redwood Valley, CA
  12. 1.9 19km NW of Cloverdale, CA
  13. 2.8 10km NNE of Talmage, CA
  14. 2.4 13km WNW of Lake Pillsbury, CA
  15. 1.6 6km E 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.