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 1:50 am PST (09:50 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) south-southwest of Yountville, CA, at 10:55 am PDT on 14 March 2021 (17:55 UTC), 7.1 km deep. 1 person has reported feeling it to USGS.

USGS: 6km SSW of Yountville, CA

9 km (6 mi) NW of Napa, CA · 63 km (39 mi) N of San Francisco, CA

10:55 am PDT, Mar 14, 2021 · · 7.1 km deep · released about 11 lb of TNT

10 km30 km60 km120 km N Napa County 18 kmSolano County 40 kmMarin County 46 kmSonoma County 51 kmYolo County 56 kmContra Costa County 61 kmAlameda County 88 kmSan Francisco County 90 kmLake County 90 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
10:55 am PDT on 14 March 2021 ()
Where
6 km (4 mi) south-southwest of Yountville, CA · earthquakes near Yountville
Magnitude
M 1.7 (md)
Depth
7.1 km below the surface
Felt
1 report · strongest reported intensity I
Nearest
Napa County, 18 km NNE
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 2066 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 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.

Likely felt in: Agua Caliente 10 km, intensity II · Napa 10 km, intensity II. Estimated for each town centre; each link is that town's own record.

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 1,000,000× the energy of this one
  3. Around the size people start to feel M 3.0 89× 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 · 16 km SSE of this epicentre
  2. 5.4 South of Elmira, California · 42 km E of this epicentre
  3. 5.3 3 km E of Bloomfield, California · 37 km W of this epicentre
  4. 5.3 Northern California · 39 km W 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 38.3490, -122.3807. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Napa County, CA 18 km (11 mi) NNE earthquakes near Napa County
Solano County, CA 40 km (25 mi) ESE earthquakes near Solano County
Marin County, CA 46 km (29 mi) SW earthquakes near Marin County
Sonoma County, CA 51 km (32 mi) WNW earthquakes near Sonoma County
Yolo County, CA 56 km (34 mi) NE earthquakes near Yolo County
Contra Costa County, CA 61 km (38 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

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

  1. 1.9 5km W of Glen Ellen, CA
  2. 1.7 6km SW of Calistoga, CA
  3. 1.9 1km N of East Richmond Heights, CA
  4. 2.1 6km W of Yountville, CA
  5. 1.5 4km SW of Glen Ellen, CA
  6. 1.5 5km E of Vallejo, CA
  7. 1.6 4km W of Kenwood, CA
  8. 1.9 10km SSE of Elmira, CA
  9. 1.6 6km SSW of Calistoga, CA
  10. 1.6 3km NNW of Angwin, CA
  11. 1.6 6km SSW of Calistoga, CA
  12. 3.3 6km S of Calistoga, CA
  13. 1.6 6km ESE of Santa Venetia, CA
  14. 1.6 6km NNE of Windsor, CA
  15. 1.8 1km SW of East Richmond Heights, 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.