QuakeIndex

Earthquake · reviewed by a seismologist

M 2.5md

Earthquake near Santa Rosa, CA

No earthquake was likely felt in Santa Rosa in the 24 hours to 3:08 am PST (11:08 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 2.5 earthquake was recorded 40 km (25 mi) east-northeast of Santa Rosa, CA, at 7:47 pm PST on 6 February 2017 (03:47 UTC), 8.5 km deep.

USGS: Northern California

87 km (54 mi) N of San Francisco, CA · 29 km (18 mi) N of Napa, CA

7:47 pm PST, Feb 6, 2017 · · 8.5 km deep · released about 150 lb of TNT

10 km30 km60 km120 km N Napa County 7 kmYolo County 35 kmSolano County 44 kmSonoma County 57 kmColusa County 69 kmMarin County 70 kmSutter County 73 kmLake County 73 kmContra Costa County 76 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
7:47 pm PST on 6 February 2017 ()
Where
40 km (25 mi) east-northeast of Santa Rosa, CA · earthquakes near Santa Rosa
Magnitude
M 2.5 (md)
Depth
8.5 km below the surface
Felt
no reports yet
Nearest
Napa County, 7 km SW
Nearest mapped fault
Hunting Creek-Berryessa fault system, 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 3564 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 Santa Rosa, 40 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: Angwin 15 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

No earthquake of M4 or more has been recorded within 50 km since our catalogue begins in 2016.

Before 2016, the USGS record lists 2 earthquakes of M5 or more within 50 km:

  1. 6.0 The 2014 South Napa, California Earthquake · 38 km S of this epicentre
  2. 5.4 South of Elmira, California · 43 km SE 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 38.5578, -122.2752. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Napa County, CA 7 km (4 mi) SW earthquakes near Napa County
Yolo County, CA 35 km (22 mi) ENE earthquakes near Yolo County
Solano County, CA 44 km (27 mi) SE earthquakes near Solano County
Sonoma County, CA 57 km (35 mi) W earthquakes near Sonoma County
Colusa County, CA 69 km (43 mi) N earthquakes near Colusa County
Marin County, CA 70 km (43 mi) SW earthquakes near Marin County

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

Aftershocks so far

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

  1. 1.7 6 km S of Cobb, California
  2. 1.6 7 km W of Middletown, California
  3. 1.6 7 km W of Middletown, California
  4. 1.8 3 km S of Cobb, California
  5. 1.6 7 km S of Cobb, California
  6. 1.6 2 km S of Cobb, California
  7. 1.6 3 km S of Cobb, California
  8. 1.8 3 km SSW of Cobb, California
  9. 4.2 3 km SSW of Cobb, California
  10. 1.9 3 km SSW of Cobb, California
  11. 1.7 6 km S of Cobb, California
  12. 2.2 6 km WSW of Moskowite Corner, California
  13. 1.5 2 km SSW of Cobb, California
  14. 2.0 14 km NNW of Moskowite Corner, California
  15. 2.3 14 km E of Angwin, California

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.