QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Santa Rosa, CA

No earthquake was likely felt in Santa Rosa in the 24 hours to 11:22 pm PST (07:22 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 1.7 earthquake was recorded 42 km (26 mi) east-northeast of Santa Rosa, CA, at 10:40 pm PDT on 26 July 2017 (05:40 UTC), 8.0 km deep.

USGS: 13 km NNW of Moskowite Corner, California

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

10:40 pm PDT, Jul 26, 2017 · · 8.0 km deep · released about 9.3 lb of TNT

Every earthquake near Santa Rosa Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Napa County 9 kmYolo County 33 kmSolano County 42 kmSonoma County 59 kmColusa County 69 kmMarin County 71 kmSutter County 71 kmLake County 75 kmContra Costa County 75 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
10:40 pm PDT on 26 July 2017 ()
Where
42 km (26 mi) east-northeast of Santa Rosa, CA · earthquakes near Santa Rosa
Magnitude
M 1.7 (md)
Depth
8.0 km below the surface
Felt
no reports yet
Nearest
Napa County, 9 km SW
Nearest mapped fault
Hunting Creek-Berryessa fault system, under 1 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 3386 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 9 km (6 mi) from the epicentre. In Santa Rosa, 42 km away, the estimate is intensity I (not felt). 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.

Earthquakes near other towns within 30 km: Angwin, Deer Park, Yountville, Saint Helena, Winters, Esparto.

How big was it?

This earthquake released about 9.3 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,600,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,100,000× the energy of this one
  3. Around the size people start to feel M 3.0 100× the energy of this one
  4. This earthquake M 1.7 about 9.3 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 · 42 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 38.5543, -122.2488. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Napa County, CA 9 km (5 mi) SW earthquakes near Napa County
Yolo County, CA 33 km (21 mi) ENE earthquakes near Yolo County
Solano County, CA 42 km (26 mi) SE earthquakes near Solano County
Sonoma County, CA 59 km (37 mi) W earthquakes near Sonoma County
Colusa County, CA 69 km (43 mi) N earthquakes near Colusa County
Marin County, CA 71 km (44 mi) SW earthquakes near Marin County

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

Aftershocks so far

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

  1. 1.6 7 km S of Cobb, California
  2. 1.7 7 km S of Cobb, California
  3. 1.6 3 km S of Cobb, California
  4. 3.5 11 km WNW of Calistoga, California
  5. 1.7 5 km S of Cobb, California
  6. 1.6 5 km SSW of Cobb, California
  7. 1.9 4 km SSW of Cobb, California
  8. 1.6 5 km SSW of Cobb, California
  9. 1.8 1km SSW of Anderson Springs, CA
  10. 1.9 14 km WSW of Esparto, California
  11. 1.5 5 km S of Cobb, California
  12. 1.8 7 km ENE of Napa, California
  13. 2.3 4 km SSW of Cobb, California
  14. 2.3 6 km N of Kenwood, California
  15. 1.6 4km SSW of Anderson Springs, 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.