QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Yountville, CA

No earthquake was likely felt in Yountville in the 24 hours to 12:17 am PST (08:17 UTC). The last one was M 2.4, 19 km (12 mi) SSE, at 10:47 am PDT on 6 October 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Yountville

This page: a magnitude 1.7 earthquake was recorded 6 km (4 mi) west of Yountville, CA, at 8:06 pm PDT on 30 September 2019 (03:06 UTC), 9.5 km deep.

USGS: 6km W of Yountville, CA

70 km (43 mi) N of San Francisco, CA · 17 km (10 mi) NW of Napa, CA

8:06 pm PDT, Sep 30, 2019 · · 9.5 km deep · released about 11 lb of TNT

10 km30 km60 km120 km N Napa County 15 kmSonoma County 45 kmSolano County 46 kmMarin County 48 kmYolo County 55 kmContra Costa County 68 kmLake County 83 kmColusa County 88 kmSan Francisco County 92 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
8:06 pm PDT on 30 September 2019 ()
Where
6 km (4 mi) west of Yountville, CA · earthquakes near Yountville
Magnitude
M 1.7 (md)
Depth
9.5 km below the surface
Felt
no reports yet
Nearest
Napa County, 15 km NE
Nearest mapped fault
West Napa fault, 2 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 1695 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 8 km (5 mi) from the epicentre. In Yountville, 6 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: Eldridge, Kenwood, Agua Caliente, Fetters Hot Springs-Agua Caliente, Boyes Hot Springs, Saint Helena.

How big was it?

This earthquake released about 11 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 1,400,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 970,000× the energy of this one
  3. Around the size people start to feel M 3.0 86× the energy of this one
  4. This earthquake M 1.7 about 11 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 4 earthquakes of M5 or more within 50 km:

  1. 6.0 The 2014 South Napa, California Earthquake · 24 km SSE of this epicentre
  2. 5.4 South of Elmira, California · 48 km ESE of this epicentre
  3. 5.3 3 km E of Bloomfield, California · 34 km WSW of this epicentre
  4. 5.3 Northern California · 35 km WSW 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 38.4043, -122.4338. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Napa County, CA 15 km (9 mi) NE earthquakes near Napa County
Sonoma County, CA 45 km (28 mi) WNW earthquakes near Sonoma County
Solano County, CA 46 km (28 mi) ESE earthquakes near Solano County
Marin County, CA 48 km (30 mi) SW earthquakes near Marin County
Yolo County, CA 55 km (34 mi) ENE earthquakes near Yolo County
Contra Costa County, CA 68 km (43 mi) SE earthquakes near Contra Costa County

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

Aftershocks so far

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

  1. 1.7 2km SE of The Geysers, CA
  2. 1.6 3km SE of The Geysers, CA
  3. 2.0 7km WSW of St. Helena, CA
  4. 2.0 3km SSE of The Geysers, CA
  5. 1.9 3km WSW of Anderson Springs, CA
  6. 2.1 1km ESE of The Geysers, CA
  7. 1.7 14km E of Angwin, CA
  8. 1.8 14km E of Angwin, CA
  9. 1.7 14km E of Angwin, CA
  10. 1.6 4km SW of Anderson Springs, CA
  11. 1.8 2km ENE of The Geysers, CA
  12. 2.1 3km SE of The Geysers, CA
  13. 2.1 3km SE of The Geysers, CA
  14. 1.7 2km ESE of The Geysers, CA
  15. 1.9 4km SSW of Vallejo, 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.