QuakeIndex

Earthquake · reviewed by a seismologist

M 1.9md

Earthquake near Arbuckle, CA

No earthquake was likely felt in Arbuckle in the 24 hours to 5:50 am PST (13:50 UTC). The last one was M 4.0, 94 km (58 mi) NW, at 5:01 am PDT on 28 October 2026, estimated intensity II (weak) in town; 14 felt reports to USGS. Every earthquake near Arbuckle

This page: a magnitude 1.9 earthquake was recorded 8 km (5 mi) west-southwest of Arbuckle, CA, at 12:03 am PDT on 20 May 2026 (07:03 UTC), 17 km deep.

USGS: 8 km WSW of Arbuckle, CA

76 km (47 mi) NW of Sacramento, CA · 46 km (29 mi) WSW of Yuba City, CA

12:03 am PDT, May 20, 2026 · · 17 km deep · released about 20 lb of TNT

10 km30 km60 km120 km N Colusa County 21 kmSutter County 39 kmYolo County 42 kmLake County 53 kmNapa County 57 kmGlenn County 70 kmYuba County 76 kmSolano County 84 kmSonoma County 86 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 PDT on 20 May 2026 ()
Where
8 km (5 mi) west-southwest of Arbuckle, CA · earthquakes near Arbuckle
Magnitude
M 1.9 (md)
Depth
17 km below the surface
Felt
no reports yet
Nearest
Colusa County, 21 km NNW
Nearest mapped fault
Great Valley thrust fault system, 5 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 166 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 Arbuckle, 8 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: Williams, Dunnigan, Colusa.

How big was it?

This earthquake released about 20 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 5.8 760,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 540,000× the energy of this one
  3. Around the size people start to feel M 3.0 48× the energy of this one
  4. This earthquake M 1.9 about 20 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

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 39.0005, -122.1502. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Colusa County, CA 21 km (13 mi) NNW earthquakes near Colusa County
Sutter County, CA 39 km (24 mi) E earthquakes near Sutter County
Yolo County, CA 42 km (26 mi) SSE earthquakes near Yolo County
Lake County, CA 53 km (33 mi) WNW earthquakes near Lake County
Napa County, CA 57 km (35 mi) SSW earthquakes near Napa County
Glenn County, CA 70 km (44 mi) NNW earthquakes near Glenn County

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

Aftershocks so far

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

  1. 2.8 8 km E of Lower Lake, CA
  2. 2.2 7 km ESE of Lower Lake, CA
  3. 1.5 8 km ESE of Lower Lake, CA
  4. 2.1 7 km ESE of Lower Lake, CA
  5. 2.5 8 km E of Lower Lake, CA
  6. 1.4 12 km NNE of Angwin, CA
  7. 1.8 13 km SE of Middletown, CA
  8. 2.0 5 km E of Williams, CA
  9. 1.5 11 km ENE of Hidden Valley Lake, CA
  10. 2.4 2 km N of Middletown, CA
  11. 1.6 14 km ESE of Hidden Valley Lake, CA
  12. 1.9 7 km ESE of Williams, CA
  13. 1.5 13 km SE of Middletown, CA
  14. 2.0 5 km E of Hidden Valley Lake, CA
  15. 2.6 12 km SE of Middletown, 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.