QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

Earthquake near Calistoga, CA

No earthquake was likely felt in Calistoga in the 24 hours to 5:09 am PST (13:09 UTC). The last one was M 3.0, 33 km (21 mi) NW, at 11:06 pm PDT on 14 October 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Calistoga

This page: a magnitude 3.3 earthquake was recorded 6 km (4 mi) south of Calistoga, CA, at 7:13 am PDT on 10 April 2021 (14:13 UTC), 9.1 km deep. 262 people have reported feeling it to USGS.

USGS: 6km S of Calistoga, CA

14 km (8 mi) NE of Santa Rosa, CA

7:13 am PDT, Apr 10, 2021 · · 9.1 km deep · released about 1.2 tons of TNT

10 km30 km60 km120 km N Napa County 23 kmSonoma County 30 kmMarin County 54 kmYolo County 62 kmSolano County 63 kmLake County 67 kmColusa County 79 kmContra Costa County 87 kmSutter County 95 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
7:13 am PDT on 10 April 2021 ()
Where
6 km (4 mi) south of Calistoga, CA · earthquakes near Calistoga
Magnitude
M 3.3 (ml)
Depth
9.1 km below the surface
Felt
262 reports · strongest reported intensity III
Nearest
Napa County, 23 km E
Nearest mapped fault
Maacama 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 1906 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 49 km (30 mi) from the epicentre. In Calistoga, 6 km away, the estimate is intensity III (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: Calistoga 6 km, intensity III · Kenwood 13 km, intensity III · Angwin 13 km, intensity III · Santa Rosa 15 km, intensity III · Windsor 20 km, intensity II · Rohnert Park 23 km, intensity II · Agua Caliente 24 km, intensity II · Healdsburg 27 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.2 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.3 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 140,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 6,500× the energy of this one
  3. Magna, Utah 2020 M 5.7 4,600× the energy of this one
  4. This earthquake M 3.3 about 1.2 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 2.5× more

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 420 times the energy of this one.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 6.0 The 2014 South Napa, California Earthquake · 42 km SE of this epicentre
  2. 5.3 3 km E of Bloomfield, California · 30 km SW of this epicentre
  3. 5.3 Northern California · 31 km SW 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 38.5227, -122.5848. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Napa County, CA 23 km (14 mi) E earthquakes near Napa County
Sonoma County, CA 30 km (18 mi) W earthquakes near Sonoma County
Marin County, CA 54 km (34 mi) SSW earthquakes near Marin County
Yolo County, CA 62 km (38 mi) ENE earthquakes near Yolo County
Solano County, CA 63 km (39 mi) ESE earthquakes near Solano County
Lake County, CA 67 km (41 mi) NNW earthquakes near Lake County

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

Aftershocks so far

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

  1. 2.0 5km NNW of The Geysers, CA
  2. 1.6 6km NW of The Geysers, CA
  3. 3.1 2km SSW of Anderson Springs, CA
  4. 1.7 6km NW of The Geysers, CA
  5. 2.3 1km NNW of The Geysers, CA
  6. 1.7 8km NW of The Geysers, CA
  7. 2.6 3km WSW of Anderson Springs, CA
  8. 1.8 6km NNW of The Geysers, CA
  9. 1.5 6km WNW of The Geysers, CA
  10. 1.8 7km NW of The Geysers, CA
  11. 2.8 1km W of Anderson Springs, CA
  12. 1.6 4km W of Kenwood, CA
  13. 1.6 6km WNW of Cobb, CA
  14. 2.4 2km NE of Anderson Springs, CA
  15. 2.5 6km NW 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.