QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5md

Earthquake near Yountville, CA

No earthquake was likely felt in Yountville in the 24 hours to 6:56 pm PST (02:56 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 2.5 earthquake was recorded 6 km (4 mi) west of Yountville, CA, at 4:51 am PDT on 13 August 2020 (11:51 UTC), 8.3 km deep. 28 people have reported feeling it to USGS.

USGS: 6km W of Yountville, CA

70 km (44 mi) N of San Francisco, CA · 17 km (10 mi) NW of Napa, CA

4:51 am PDT, Aug 13, 2020 · · 8.3 km deep · released about 150 lb of TNT

10 km30 km60 km120 km N Napa County 14 kmSonoma County 45 kmSolano County 46 kmMarin County 49 kmYolo County 55 kmContra Costa County 69 kmLake County 82 kmColusa County 87 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
4:51 am PDT on 13 August 2020 ()
Where
6 km (4 mi) west of Yountville, CA · earthquakes near Yountville
Magnitude
M 2.5 (md)
Depth
8.3 km below the surface
Felt
28 reports · strongest reported intensity III
Nearest
Napa County, 14 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 2210 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 20 km (12 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: Kenwood 10 km, intensity II · Agua Caliente 11 km, intensity II · Napa 18 km, intensity II · Angwin 19 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 150 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 100,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 72,000× the energy of this one
  3. Around the size people start to feel M 3.0 6.5× the energy of this one
  4. This earthquake M 2.5 about 150 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 4.2 on 2018-01-18 — about 440 times the energy of this one.

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 · 35 km WSW of this epicentre
  4. 5.3 Northern California · 36 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 38.4098, -122.4293. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Napa County, CA 14 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 49 km (30 mi) SW earthquakes near Marin County
Yolo County, CA 55 km (34 mi) ENE earthquakes near Yolo County
Contra Costa County, CA 69 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

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

  1. 1.5 8km WNW of Yountville, CA
  2. 2.7 2km SSE of Crockett, CA
  3. 2.2 3km SW of Anderson Springs, CA
  4. 1.6 6km ESE of Santa Rosa, CA
  5. 1.7 2km ENE of The Geysers, CA
  6. 1.8 4km SSE of The Geysers, CA
  7. 1.7 6km E of Santa Rosa, CA
  8. 1.7 3km W of Anderson Springs, CA
  9. 1.8 3km SE of The Geysers, CA
  10. 1.6 15km ENE of Yountville, CA
  11. 1.9 13km ENE of Yountville, CA
  12. 2.1 6km SW of Calistoga, CA
  13. 1.9 7km WSW of Kenwood, CA
  14. 2.3 2km WSW of Anderson Springs, CA
  15. 1.9 11km ENE of Healdsburg, 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.