QuakeIndex

Earthquake · reviewed by a seismologist

M 2.0md

Earthquake near Boonville, CA

No earthquake was likely felt in Boonville in the 24 hours to 3:29 am PST (11:29 UTC). The last one was M 4.0, 65 km (41 mi) NNE, at 5:01 am PDT on 28 October 2026, estimated intensity II (weak) in town; 14 felt reports to USGS. Every earthquake near Boonville

This page: a magnitude 2.0 earthquake was recorded 12 km (8 mi) east-southeast of Boonville, CA, at 5:02 pm PDT on 25 September 2021 (00:02 UTC), less than 1 km deep.

USGS: 12km ESE of Boonville, CA

5:02 pm PDT, Sep 25, 2021 · · 0.3 km deep · released about 28 lb of TNT

10 km30 km60 km120 km N Lake County 47 kmSonoma County 55 kmMendocino County 56 kmColusa County 91 kmNapa County 94 kmGlenn County 103 kmMarin County 109 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
5:02 pm PDT on 25 September 2021 ()
Where
12 km (8 mi) east-southeast of Boonville, CA · earthquakes near Boonville
Magnitude
M 2.0 (md)
Depth
0.3 km below the surface
Felt
no reports yet
Nearest
Lake County, 47 km ENE
Nearest mapped fault
Maacama fault, 16 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 1871 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 16 km (10 mi) from the epicentre. In Boonville, 12 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.

Likely felt in: Boonville 12 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 28 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.0 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 540,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 380,000× the energy of this one
  3. Around the size people start to feel M 3.0 34× the energy of this one
  4. This earthquake M 2.0 about 28 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 5.0 on 2016-12-14 — about 35,000 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 · 22 km NE 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 38.9508, -123.2448. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Lake County, CA 47 km (29 mi) ENE earthquakes near Lake County
Sonoma County, CA 55 km (34 mi) SSE earthquakes near Sonoma County
Mendocino County, CA 56 km (35 mi) NNW earthquakes near Mendocino County
Colusa County, CA 91 km (56 mi) ENE earthquakes near Colusa County
Napa County, CA 94 km (58 mi) ESE earthquakes near Napa County
Glenn County, CA 103 km (64 mi) NE earthquakes near Glenn County

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

Aftershocks so far

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

  1. 2.7 5km WNW of The Geysers, CA
  2. 1.9 3km N of The Geysers, CA
  3. 1.5 3km N of The Geysers, CA
  4. 3.1 1km NNW of The Geysers, CA
  5. 1.6 1km NNW of The Geysers, CA
  6. 1.7 8km W of Cobb, CA
  7. 1.5 2km NNW of The Geysers, CA
  8. 2.0 3km WNW of Cobb, CA
  9. 2.4 4km NW of The Geysers, CA
  10. 1.6 7km WNW of Cobb, CA
  11. 1.7 9km NW of The Geysers, CA
  12. 1.8 9km WNW of The Geysers, CA
  13. 1.6 2km NE of The Geysers, CA
  14. 3.0 14km N of Cloverdale, CA
  15. 1.5 10km N of Cloverdale, 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.