QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Santa Rosa, CA

No earthquake was likely felt in Santa Rosa in the 24 hours to 10:38 pm PST (06:38 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 1.8 earthquake was recorded 6 km (4 mi) east-northeast of Santa Rosa, CA, at 5:50 pm PDT on 8 October 2016 (00:50 UTC), 7.0 km deep.

USGS: 6 km ENE of Santa Rosa, California

5 km (3 mi) ENE of Santa Rosa, CA

5:50 pm PDT, Oct 8, 2016 · · 7.0 km deep · released about 15 lb of TNT

Every earthquake near Santa Rosa Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Sonoma County 25 kmNapa County 29 kmMarin County 46 kmSolano County 65 kmYolo County 69 kmLake County 73 kmContra Costa County 85 kmSan Francisco County 88 kmColusa County 88 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
5:50 pm PDT on 8 October 2016 ()
Where
6 km (4 mi) east-northeast of Santa Rosa, CA · earthquakes near Santa Rosa
Magnitude
M 1.8 (md)
Depth
7.0 km below the surface
Felt
no reports yet
Nearest
Sonoma County, 25 km WNW
Nearest mapped fault
Rodgers Creek fault, 3 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 3561 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 12 km (7 mi) from the epicentre. In Santa Rosa, 6 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: Santa Rosa 6 km, intensity II · Kenwood 10 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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 3 earthquakes of M5 or more within 50 km:

  1. 6.0 The 2014 South Napa, California Earthquake · 40 km SE of this epicentre
  2. 5.3 3 km E of Bloomfield, California · 21 km SW of this epicentre
  3. 5.3 Northern California · 22 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 38.4557, -122.6480. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sonoma County, CA 25 km (16 mi) WNW earthquakes near Sonoma County
Napa County, CA 29 km (18 mi) ENE earthquakes near Napa County
Marin County, CA 46 km (28 mi) S earthquakes near Marin County
Solano County, CA 65 km (41 mi) ESE earthquakes near Solano County
Yolo County, CA 69 km (43 mi) ENE earthquakes near Yolo County
Lake County, CA 73 km (45 mi) N earthquakes near Lake 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. 1.8 4 km SSW of Cobb, California
  2. 1.8 6 km WNW of Cobb, California
  3. 2.4 6 km WNW of Cobb, California
  4. 1.9 10 km W of Cobb, California
  5. 2.9 5 km S of Cobb, California
  6. 1.8 4 km WNW of Cobb, California
  7. 2.5 7 km W of Cobb, California
  8. 2.0 7 km W of Cobb, California
  9. 1.9 7 km W of Cobb, California
  10. 1.5 6 km W of Middletown, California
  11. 1.9 6 km W of Middletown, California
  12. 1.9 6 km W of Middletown, California
  13. 2.0 8 km WNW of Cobb, California
  14. 1.9 8 km W of Cobb, California
  15. 1.9 8 km WNW of Cobb, 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.