QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

Earthquake near Boonville, CA

No earthquake was likely felt in Boonville in the 24 hours to 10:40 am PST (18:40 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 1.5 earthquake was recorded 34 km (21 mi) west of Boonville, CA, at 2:47 am PST on 13 November 2021 (10:47 UTC), 2.1 km deep.

USGS: 10km NW of Point Arena, CA

2:47 am PST, Nov 13, 2021 · · 2.1 km deep · released about 5.7 lb of TNT

10 km30 km60 km120 km N Mendocino County 57 kmSonoma County 89 kmLake County 89 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
2:47 am PST on 13 November 2021 ()
Where
34 km (21 mi) west of Boonville, CA · earthquakes near Boonville
Magnitude
M 1.5 (md)
Depth
2.1 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 57 km NNE
Nearest mapped fault
San Andreas fault, 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 1820 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 10 km (6 mi) from the epicentre. In Boonville, 34 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.

How big was it?

This earthquake released about 5.7 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,900,000× the energy of this one
  3. Around the size people start to feel M 3.0 170× the energy of this one
  4. This earthquake M 1.5 about 5.7 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 38.9870, -123.7642. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Mendocino County, CA 57 km (35 mi) NNE earthquakes near Mendocino County
Sonoma County, CA 89 km (55 mi) SE earthquakes near Sonoma County
Lake County, CA 89 km (55 mi) E earthquakes near Lake County
Glenn County, CA 136 km (84 mi) ENE earthquakes near Glenn County
Marin County, CA 137 km (85 mi) SE earthquakes near Marin 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. 1.6 12km NNE of Point Arena, CA
  2. 2.3 13km WNW of Redwood Valley, CA
  3. 1.8 32km WNW of Point Arena, CA
  4. 1.7 16km WNW of Boonville, CA
  5. 1.6 21km WNW of Ukiah, CA
  6. 1.6 12km W of Ukiah, CA
  7. 2.0 21km WNW of Ukiah, CA
  8. 1.8 21km NNW of Boonville, CA
  9. 1.8 20km SSW of Willits, CA
  10. 1.8 20km SSW of Willits, CA
  11. 1.5 8km NE of Boonville, CA
  12. 2.0 14km WSW of Willits, CA
  13. 1.8 18km SW of Willits, CA
  14. 1.9 18km SW of Willits, CA
  15. 1.6 7km NE of Mendocino, 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.