QuakeIndex

Earthquake · reviewed by a seismologist

M 1.7md

Earthquake near Guerneville, CA

No earthquake was likely felt in Guerneville in the 24 hours to 1:25 pm PST (21:25 UTC). The last one was M 3.0, 38 km (24 mi) NNE, at 11:06 pm PDT on 14 October 2026, estimated intensity II (weak) in town; 1 felt report to USGS. Every earthquake near Guerneville

This page: a magnitude 1.7 earthquake was recorded 4 km (3 mi) north of Guerneville, CA, at 4:34 pm PST on 9 February 2017 (00:34 UTC), 3.7 km deep.

USGS: 4 km N of Guerneville, California

98 km (61 mi) NNW of San Francisco, CA · 27 km (17 mi) WNW of Santa Rosa, CA

4:34 pm PST, Feb 9, 2017 · · 3.7 km deep · released about 10 lb of TNT

10 km30 km60 km120 km N Sonoma County 6 kmNapa County 58 kmMarin County 58 kmLake County 66 kmSan Francisco County 91 kmYolo County 96 kmColusa County 96 kmSolano County 96 kmMendocino County 107 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
4:34 pm PST on 9 February 2017 ()
Where
4 km (3 mi) north of Guerneville, CA · earthquakes near Guerneville
Magnitude
M 1.7 (md)
Depth
3.7 km below the surface
Felt
no reports yet
Nearest
Sonoma County, 6 km ESE
Nearest mapped fault
Rodgers Creek fault, 17 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 3557 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 Guerneville, 4 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.

Earthquakes near other towns within 30 km: Monte Rio, Forestville, Healdsburg, Camp Meeker, Windsor, Occidental.

How big was it?

This earthquake released about 10 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 1,500,000× 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 95× the energy of this one
  4. This earthquake M 1.7 about 10 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

The largest earthquake within 50 km since 2016 was M 5.0 on 2016-12-14 — about 99,000 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 · 30 km SSE of this epicentre
  2. 5.3 Northern California · 28 km SSE 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 38.5412, -122.9875. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sonoma County, CA 6 km (3 mi) ESE earthquakes near Sonoma County
Napa County, CA 58 km (36 mi) E earthquakes near Napa County
Marin County, CA 58 km (36 mi) SSE earthquakes near Marin County
Lake County, CA 66 km (41 mi) NNE earthquakes near Lake County
San Francisco County, CA 91 km (56 mi) S earthquakes near San Francisco County
Yolo County, CA 96 km (59 mi) E earthquakes near Yolo County

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

Aftershocks so far

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

  1. 1.6 5 km W of Cobb, California
  2. 1.7 6 km S of Cobb, California
  3. 1.6 9 km WNW of Cobb, California
  4. 1.9 7 km W of Cobb, California
  5. 1.5 5 km WNW of Cobb, California
  6. 3.1 12 km WSW of Cloverdale, California
  7. 1.9 7 km S of Calistoga, California
  8. 1.5 8 km W of Cobb, California
  9. 1.9 4 km SW of Cobb, California
  10. 1.6 8 km W of Cobb, California
  11. 1.5 2 km E of Saint Helena, California
  12. 2.7 4 km S of Cobb, California
  13. 2.0 8 km WSW of Cobb, California
  14. 1.6 4 km WNW of Cobb, California
  15. 2.2 6 km W 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.