QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

Earthquake near Larkfield-Wikiup, CA

No earthquake was likely felt in Larkfield-Wikiup in the 24 hours to 4:21 am PST (12:21 UTC). The last one was M 1.9, 8 km (5 mi) ESE, at 2:01 pm PDT on 23 October 2026, estimated intensity II (weak) in town. Every earthquake near Larkfield-Wikiup

This page: a magnitude 1.8 earthquake was recorded 4 km (3 mi) north-northwest of Larkfield-Wikiup, CA, at 4:40 am PDT on 4 June 2023 (11:40 UTC), 8.7 km deep.

USGS: 4km NNW of Larkfield-Wikiup, CA

13 km (8 mi) NNW of Santa Rosa, CA

4:40 am PDT, Jun 4, 2023 · · 8.7 km deep · released about 17 lb of TNT

10 km30 km60 km120 km N Sonoma County 14 kmNapa County 38 kmMarin County 56 kmLake County 62 kmYolo County 76 kmSolano County 78 kmColusa County 83 kmSan Francisco County 95 kmContra Costa County 100 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
4:40 am PDT on 4 June 2023 ()
Where
4 km (3 mi) north-northwest of Larkfield-Wikiup, CA · earthquakes near Larkfield-Wikiup
Magnitude
M 1.8 (md)
Depth
8.7 km below the surface
Felt
no reports yet
Nearest
Sonoma County, 14 km WSW
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 1255 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 11 km (7 mi) from the epicentre. In Larkfield-Wikiup, 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.

Likely felt in: Windsor 5 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 17 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 5.8 870,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 620,000× the energy of this one
  3. Around the size people start to feel M 3.0 55× the energy of this one
  4. This earthquake M 1.8 about 17 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 57,000 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 · 27 km S of this epicentre
  2. 5.3 Northern California · 26 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 38.5513, -122.7640. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Sonoma County, CA 14 km (9 mi) WSW earthquakes near Sonoma County
Napa County, CA 38 km (24 mi) E earthquakes near Napa County
Marin County, CA 56 km (35 mi) S earthquakes near Marin County
Lake County, CA 62 km (38 mi) N earthquakes near Lake County
Yolo County, CA 76 km (47 mi) E earthquakes near Yolo County
Solano County, CA 78 km (49 mi) ESE earthquakes near Solano County

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

Aftershocks so far

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

  1. 3.3 4km SE of The Geysers, CA
  2. 2.9 4 km SSE of The Geysers, CA
  3. 3.0 4 km SSE of The Geysers, CA
  4. 2.0 6km WSW of St. Helena, CA
  5. 1.6 12km SE of Cloverdale, CA
  6. 1.6 4km NNW of The Geysers, CA
  7. 1.8 7km WSW of St. Helena, CA
  8. 1.7 6km WNW of The Geysers, CA
  9. 1.6 1km WSW of Anderson Springs, CA
  10. 1.5 8km WNW of Cobb, CA
  11. 2.1 7km W of Cobb, CA
  12. 1.6 8km NW of The Geysers, CA
  13. 2.0 7km NW of The Geysers, CA
  14. 1.7 1km NE of The Geysers, CA
  15. 1.8 1km W of Dillon Beach, 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.