QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

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 1.7 earthquake was recorded 13 km (8 mi) north-northeast of Ukiah, CA, at 10:12 am PST on 24 February 2017 (18:12 UTC), 2.3 km deep.

USGS: 7 km ENE of Calpella, California

96 km (60 mi) NNW of Santa Rosa, CA

10:12 am PST, Feb 24, 2017 · · 2.3 km deep · released about 12 lb of TNT

10 km30 km60 km120 km N Mendocino County 34 kmLake County 36 kmGlenn County 73 kmColusa County 77 kmSonoma County 82 kmNapa County 108 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
10:12 am PST on 24 February 2017 ()
Where
13 km (8 mi) north-northeast of Ukiah, CA · earthquakes near Ukiah
Magnitude
M 1.7 (md)
Depth
2.3 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 34 km NW
Nearest mapped fault
Maacama fault, 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 3547 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 13 km (8 mi) from the epicentre. In Ukiah, 13 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.

Earthquakes near other towns within 30 km: Redwood Valley, Talmage, Upper Lake, North Lakeport, Willits, Nice.

How big was it?

This earthquake released about 12 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,300,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 900,000× the energy of this one
  3. Around the size people start to feel M 3.0 80× the energy of this one
  4. This earthquake M 1.7 about 12 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 110,000 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 · 15 km S 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 39.2488, -123.1237. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 34 km (21 mi) NW earthquakes near Mendocino County
Lake County, CA 36 km (22 mi) ESE earthquakes near Lake County
Glenn County, CA 73 km (46 mi) ENE earthquakes near Glenn County
Colusa County, CA 77 km (48 mi) E earthquakes near Colusa County
Sonoma County, CA 82 km (51 mi) SSE earthquakes near Sonoma County
Napa County, CA 108 km (67 mi) SE earthquakes near Napa County

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

Aftershocks so far

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

  1. 1.5 19 km NE of Upper Lake, California
  2. 2.3 13 km SSE of Laytonville, California
  3. 1.7 9 km N of Philo, California
  4. 1.7 18 km NNE of Upper Lake, California
  5. 1.6 18 km NE of Upper Lake, California
  6. 2.0 18 km NE of Upper Lake, California
  7. 1.5 9 km ESE of Calpella, California
  8. 2.1 17 km NE of Upper Lake, California
  9. 1.7 9 km N of Redwood Valley, California
  10. 2.3 7 km SSW of Philo, California
  11. 2.2 4 km E of Willits, California
  12. 1.7 11 km SSE of Laytonville, California
  13. 2.4 28 km NNE of Potter Valley, California
  14. 1.7 10km SE of Lake Pillsbury, CA
  15. 1.6 10km SSE of Lake Pillsbury, 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.