QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Healdsburg, CA

No earthquake was likely felt in Healdsburg in the 24 hours to 2:30 am PST (10:30 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 1.7 earthquake was recorded 9 km (6 mi) north-northeast of Healdsburg, CA, at 5:13 am PDT on 12 June 2020 (12:13 UTC), 4.9 km deep.

USGS: 10km NNE of Healdsburg, CA

28 km (17 mi) NNW of Santa Rosa, CA · 106 km (66 mi) NNW of San Francisco, CA

5:13 am PDT, Jun 12, 2020 · · 4.9 km deep · released about 9.6 lb of TNT

10 km30 km60 km120 km N Sonoma County 20 kmNapa County 47 kmLake County 48 kmMarin County 71 kmColusa County 74 kmYolo County 79 kmSolano County 89 kmMendocino County 99 kmSutter County 104 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
5:13 am PDT on 12 June 2020 ()
Where
9 km (6 mi) north-northeast of Healdsburg, CA · earthquakes near Healdsburg
Magnitude
M 1.7 (md)
Depth
4.9 km below the surface
Felt
no reports yet
Nearest
Sonoma County, 20 km SSW
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 2340 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 11 km (7 mi) from the epicentre. In Healdsburg, 9 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 9 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 9.6 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 1,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 99× the energy of this one
  4. This earthquake M 1.7 about 9.6 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 100,000 times the energy of this one.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 5.3 3 km E of Bloomfield, California · 41 km S of this epicentre
  2. 5.3 Northern California · 40 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 38.6840, -122.8143. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sonoma County, CA 20 km (13 mi) SSW earthquakes near Sonoma County
Napa County, CA 47 km (29 mi) ESE earthquakes near Napa County
Lake County, CA 48 km (30 mi) N earthquakes near Lake County
Marin County, CA 71 km (44 mi) S earthquakes near Marin County
Colusa County, CA 74 km (46 mi) NE earthquakes near Colusa County
Yolo County, CA 79 km (49 mi) E earthquakes near Yolo County

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

Aftershocks so far

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

  1. 1.8 6km NW of The Geysers, CA
  2. 2.4 3km W of Cobb, CA
  3. 1.6 12km E of Angwin, CA
  4. 1.6 3km NE of The Geysers, CA
  5. 2.5 4km NW of The Geysers, CA
  6. 1.5 9km NNW of Healdsburg, CA
  7. 1.8 4km W of Cobb, CA
  8. 1.9 6km WNW of The Geysers, CA
  9. 2.0 4km SW of Anderson Springs, CA
  10. 2.4 4km SE of The Geysers, CA
  11. 2.0 7km NW of The Geysers, CA
  12. 1.5 4km WNW of The Geysers, CA
  13. 2.3 13km W of Lakeport, CA
  14. 1.9 5km W of Cobb, CA
  15. 2.0 2km ESE of The Geysers, 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.