QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

Earthquake near Healdsburg, CA

No earthquake was likely felt in Healdsburg in the 24 hours to 12:48 am PST (08:48 UTC). The last one was M 2.6, 22 km (14 mi) NNE, at 4:44 pm PST on 8 November 2026, estimated intensity II (weak) in town. Every earthquake near Healdsburg

This page: a magnitude 2.1 earthquake was recorded 10 km (6 mi) northeast of Healdsburg, CA, at 5:18 pm PST on 12 November 2016 (01:18 UTC), 2.2 km deep.

USGS: 9 km NE of Healdsburg, California

25 km (15 mi) NNW of Santa Rosa, CA · 103 km (64 mi) NNW of San Francisco, CA

5:18 pm PST, Nov 12, 2016 · · 2.2 km deep · released about 38 lb of TNT

10 km30 km60 km120 km N Sonoma County 20 kmNapa County 43 kmLake County 50 kmMarin County 68 kmColusa County 74 kmYolo County 76 kmSolano County 85 kmSutter County 102 kmMendocino County 103 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
5:18 pm PST on 12 November 2016 ()
Where
10 km (6 mi) northeast of Healdsburg, CA · earthquakes near Healdsburg
Magnitude
M 2.1 (md)
Depth
2.2 km below the surface
Felt
no reports yet
Nearest
Sonoma County, 20 km SW
Nearest mapped fault
Maacama fault, under 1 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 3561 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 17 km (11 mi) from the epicentre. In Healdsburg, 10 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: Healdsburg 10 km, intensity II · Windsor 13 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 38 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 390,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 280,000× the energy of this one
  3. Around the size people start to feel M 3.0 25× the energy of this one
  4. This earthquake M 2.1 about 38 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 lists 2 earthquakes of M5 or more within 50 km:

  1. 5.3 3 km E of Bloomfield, California · 39 km S of this epicentre
  2. 5.3 Northern California · 38 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 38.6613, -122.7765. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sonoma County, CA 20 km (12 mi) SW earthquakes near Sonoma County
Napa County, CA 43 km (27 mi) ESE earthquakes near Napa County
Lake County, CA 50 km (31 mi) N earthquakes near Lake County
Marin County, CA 68 km (42 mi) S earthquakes near Marin County
Colusa County, CA 74 km (46 mi) NE earthquakes near Colusa County
Yolo County, CA 76 km (47 mi) E earthquakes near Yolo County

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

Aftershocks so far

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

  1. 2.4 7 km NNE of Hopland, California
  2. 1.7 10 km WNW of Cobb, California
  3. 1.5 7 km WSW of Cobb, California
  4. 1.9 6 km S of Cobb, California
  5. 1.6 11 km W of Cobb, California
  6. 1.7 10 km W of Cobb, California
  7. 1.9 7 km NNE of Hopland, California
  8. 2.0 5 km SSW of Cobb, California
  9. 1.7 3 km ESE of Lower Lake, California
  10. 1.9 10 km W of Cobb, California
  11. 2.0 5 km SSW of Cobb, California
  12. 1.8 7 km W of Cobb, California
  13. 1.6 6 km W of Cobb, California
  14. 1.9 7 km W of Cobb, California
  15. 1.9 10 km W of Cobb, California

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.