QuakeIndex

Earthquake · reviewed by a seismologist

M 2.7md

Earthquake near Santa Rosa, CA

No earthquake was likely felt in Santa Rosa in the 24 hours to 4:27 am PST (12:27 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 2.7 earthquake was recorded 4 km (2 mi) north of Santa Rosa, CA, at 8:22 pm PST on 18 January 2021 (04:22 UTC), 4.8 km deep. 1,374 people have reported feeling it to USGS.

USGS: 3km NNW of Santa Rosa, CA

in Santa Rosa, CA

8:22 pm PST, Jan 18, 2021 · · 4.8 km deep · released about 320 lb of TNT

Every earthquake near Santa Rosa Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Sonoma County 19 kmNapa County 34 kmMarin County 47 kmLake County 70 kmSolano County 72 kmYolo County 74 kmSan Francisco County 88 kmColusa County 88 kmContra Costa County 91 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
8:22 pm PST on 18 January 2021 ()
Where
4 km (2 mi) north of Santa Rosa, CA · earthquakes near Santa Rosa
Magnitude
M 2.7 (md)
Depth
4.8 km below the surface
Felt
1,374 reports · strongest reported intensity V
Nearest
Sonoma County, 19 km WNW
Nearest mapped fault
Rodgers Creek fault, 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 1857 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 24 km (15 mi) from the epicentre. In Santa Rosa, 4 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: Santa Rosa 4 km, intensity III · Windsor 12 km, intensity III · Rohnert Park 15 km, intensity II · Kenwood 16 km, intensity II · Calistoga 17 km, intensity II · Healdsburg 20 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 320 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.7 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 48,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 34,000× the energy of this one
  3. Around the size people start to feel M 3.0 3× the energy of this one
  4. This earthquake M 2.7 about 320 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 3,100 times the energy of this one.

Before 2016, the USGS record lists 3 earthquakes of M5 or more within 50 km:

  1. 6.0 The 2014 South Napa, California Earthquake · 46 km SE of this epicentre
  2. 5.3 3 km E of Bloomfield, California · 20 km SSW of this epicentre
  3. 5.3 Northern California · 20 km SSW 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 38.4765, -122.7175. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sonoma County, CA 19 km (12 mi) WNW earthquakes near Sonoma County
Napa County, CA 34 km (21 mi) E earthquakes near Napa County
Marin County, CA 47 km (29 mi) S earthquakes near Marin County
Lake County, CA 70 km (44 mi) N earthquakes near Lake County
Solano County, CA 72 km (45 mi) ESE earthquakes near Solano County
Yolo County, CA 74 km (46 mi) ENE earthquakes near Yolo County

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

Aftershocks so far

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

  1. 2.4 2km NE of The Geysers, CA
  2. 1.9 5km WNW of The Geysers, CA
  3. 1.6 3km SE of The Geysers, CA
  4. 1.6 7km WNW of The Geysers, CA
  5. 1.9 0km NW of The Geysers, CA
  6. 1.7 0km N of The Geysers, CA
  7. 1.7 2km W of Anderson Springs, CA
  8. 1.8 4km SE of The Geysers, CA
  9. 2.0 8km W of Cobb, CA
  10. 1.8 2km W of Anderson Springs, CA
  11. 1.9 2km NNE of The Geysers, CA
  12. 2.0 7km NW of The Geysers, CA
  13. 1.6 8km NE of Windsor, CA
  14. 2.0 7km NW of The Geysers, CA
  15. 1.6 10km WNW 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.