QuakeIndex

Earthquake · reviewed by a seismologist

M 3.9md

Earthquake near Santa Rosa, CA

No earthquake was likely felt in Santa Rosa in the 24 hours to 4:24 am PST (12:24 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 3.9 earthquake was recorded 41 km (25 mi) north of Santa Rosa, CA, at 10:46 am PST on 5 December 2024 (18:46 UTC), 2.6 km deep. 7 people have reported feeling it to USGS.

USGS: 5 km NW of The Geysers, CA

40 km (25 mi) NNW of Santa Rosa, CA · 118 km (74 mi) NNW of San Francisco, CA

10:46 am PST, Dec 5, 2024 · · 2.6 km deep · released about 9.3 tons of TNT

10 km30 km60 km120 km N Sonoma County 33 kmLake County 34 kmNapa County 53 kmColusa County 64 kmYolo County 79 kmMarin County 84 kmMendocino County 89 kmGlenn County 95 kmSolano County 96 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
10:46 am PST on 5 December 2024 ()
Where
41 km (25 mi) north of Santa Rosa, CA · earthquakes near Santa Rosa
Magnitude
M 3.9 (md)
Depth
2.6 km below the surface
Felt
7 reports · strongest reported intensity III
Measured shaking
intensity IV (ShakeMap)
Nearest
Sonoma County, 33 km SSW
Nearest mapped fault
Maacama fault, 11 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 691 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 86 km (53 mi) from the epicentre. In Santa Rosa, 41 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: Cobb 7 km, intensity IV · Cloverdale 19 km, intensity III · Healdsburg 22 km, intensity III · Clearlake 23 km, intensity III · Windsor 28 km, intensity III · Lakeport 29 km, intensity III · Calistoga 31 km, intensity III · Angwin 40 km, intensity III. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 9.3 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.9 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 18,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 810× the energy of this one
  3. Magna, Utah 2020 M 5.7 580× the energy of this one
  4. This earthquake M 3.9 about 9.3 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 19× 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 53 times the energy of this one.

Before 2016, the USGS record lists one earthquake of M5 or more within 50 km:

  1. 5.2 6 km ESE of Talmage, California · 43 km NW 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 38.8018, -122.8015. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sonoma County, CA 33 km (20 mi) SSW earthquakes near Sonoma County
Lake County, CA 34 km (21 mi) N earthquakes near Lake County
Napa County, CA 53 km (33 mi) SE earthquakes near Napa County
Colusa County, CA 64 km (40 mi) NE earthquakes near Colusa County
Yolo County, CA 79 km (49 mi) E earthquakes near Yolo County
Marin County, CA 84 km (52 mi) S earthquakes near Marin County

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

Aftershocks so far

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

  1. 2.3 7 km WNW of Cobb, CA
  2. 1.8 11 km SSE of Talmage, CA
  3. 1.7 9 km NW of The Geysers, CA
  4. 2.4 2 km NW of The Geysers, CA
  5. 2.2 8 km NNW of The Geysers, CA
  6. 1.7 6 km NW of The Geysers, CA
  7. 1.7 6 km WNW of Cobb, CA
  8. 1.5 2 km ESE of The Geysers, CA
  9. 1.8 12 km ESE of Hidden Valley Lake, CA
  10. 2.6 3 km ENE of Saint Helena, CA
  11. 1.7 12 km WSW of Lakeport, CA
  12. 2.4 4 km ENE of Saint Helena, CA
  13. 1.6 3 km of Saint Helena, CA
  14. 1.5 10 km NNE of Larkfield-Wikiup, CA
  15. 1.7 3 km 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.