QuakeIndex

Earthquake · reviewed by a seismologist

M 3.3ml

Earthquake near Santa Rosa, CA

No earthquake was likely felt in Santa Rosa in the 24 hours to 6:48 pm PST (02:48 UTC). The last one was M 1.9, 5 km (3 mi) NE, at 2:01 pm PDT on 23 October 2026, estimated intensity II (weak) in town. Every earthquake near Santa Rosa

This page: a magnitude 3.3 earthquake was recorded 34 km (21 mi) north of Santa Rosa, CA, at 10:30 pm PDT on 8 July 2023 (05:30 UTC), 1.5 km deep. 28 people have reported feeling it to USGS.

USGS: 4km SE of The Geysers, CA

34 km (21 mi) N of Santa Rosa, CA · 111 km (69 mi) NNW of San Francisco, CA

10:30 pm PDT, Jul 8, 2023 · · 1.5 km deep · released about 1.5 tons of TNT

Every earthquake near Santa Rosa Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Sonoma County 30 kmLake County 40 kmNapa County 44 kmColusa County 64 kmYolo County 72 kmMarin County 78 kmSolano County 87 kmSutter County 94 kmMendocino County 98 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
10:30 pm PDT on 8 July 2023 ()
Where
34 km (21 mi) north of Santa Rosa, CA · earthquakes near Santa Rosa
Magnitude
M 3.3 (ml)
Depth
1.5 km below the surface
Felt
28 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
Nearest
Sonoma County, 30 km SW
Nearest mapped fault
Maacama fault, 10 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 1153 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 54 km (34 mi) from the epicentre. In Santa Rosa, 34 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: Cobb 8 km, intensity III · Healdsburg 20 km, intensity III · Calistoga 23 km, intensity III · Windsor 24 km, intensity II · Clearlake 25 km, intensity II · Cloverdale 26 km, intensity II · Angwin 31 km, intensity II · Santa Rosa 34 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 1.5 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 6.7 110,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 4,900× the energy of this one
  3. Magna, Utah 2020 M 5.7 3,500× the energy of this one
  4. This earthquake M 3.3 about 1.5 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 3.2× 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 320 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 · 49 km S of this epicentre
  2. 5.3 Northern California · 48 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 38.7495, -122.7315. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sonoma County, CA 30 km (19 mi) SW earthquakes near Sonoma County
Lake County, CA 40 km (25 mi) N earthquakes near Lake County
Napa County, CA 44 km (28 mi) SE earthquakes near Napa County
Colusa County, CA 64 km (40 mi) NE earthquakes near Colusa County
Yolo County, CA 72 km (45 mi) E earthquakes near Yolo County
Marin County, CA 78 km (48 mi) S earthquakes near Marin 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. 1.8 6 km W of Cobb, CA
  2. 1.7 8 km WNW of Cobb, CA
  3. 1.5 7 km SSW of Calistoga, CA
  4. 1.6 6 km NW of The Geysers, CA
  5. 1.7 13 km NW of The Geysers, CA
  6. 1.7 3 km SSW of Cobb, CA
  7. 1.6 7 km NW of The Geysers, CA
  8. 1.9 3 km NW of The Geysers, CA
  9. 1.7 3 km NW of The Geysers, CA
  10. 1.7 9 km WNW of Cobb, CA
  11. 1.8 6 km NW of The Geysers, CA
  12. 2.2 7 km NW of The Geysers, CA
  13. 2.1 7 km NW of The Geysers, CA
  14. 2.3 7 km NW of The Geysers, CA
  15. 2.0 14 km W of Lakeport, 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.