QuakeIndex

Earthquake · reviewed by a seismologist

M 1.6md

12 km ENE of Healdsburg, CA

· 6.6 km deep · released about 8.7 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Sonoma County 22 kmNapa County 41 kmLake County 49 kmMarin County 68 kmColusa County 72 kmYolo County 74 kmSolano County 84 kmSutter County 100 kmMendocino County 104 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
Magnitude
M 1.6 (md)
Depth
6.6 km below the surface
Felt
no reports yet
Nearest
Sonoma County, 22 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 432 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 8.7 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,700,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,200,000× the energy of this one
  3. Around the size people start to feel M 3.0 110× the energy of this one
  4. This earthquake M 1.6 about 8.7 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.

Where

Epicentre 38.6662, -122.7565. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Sonoma County, CA 22 km (13 mi) NE of here earthquakes near Sonoma County
Napa County, CA 41 km (26 mi) WNW of here earthquakes near Napa County
Lake County, CA 49 km (31 mi) S of here earthquakes near Lake County
Marin County, CA 68 km (42 mi) N of here earthquakes near Marin County
Colusa County, CA 72 km (45 mi) SW of here earthquakes near Colusa County
Yolo County, CA 74 km (46 mi) W of here earthquakes near Yolo 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. 2.2 8 km NNW of The Geysers, CA
  2. 1.7 6 km NW of The Geysers, CA
  3. 1.7 6 km WNW of Cobb, CA
  4. 1.5 2 km ESE of The Geysers, CA
  5. 1.8 12 km ESE of Hidden Valley Lake, CA
  6. 2.6 3 km ENE of Saint Helena, CA
  7. 1.7 12 km WSW of Lakeport, CA
  8. 2.4 4 km ENE of Saint Helena, CA
  9. 1.6 3 km of Saint Helena, CA
  10. 1.5 10 km NNE of Larkfield-Wikiup, CA
  11. 1.7 3 km NW of The Geysers, CA
  12. 1.6 9 km NW of The Geysers, CA
  13. 2.0 12 km W of Lakeport, CA
  14. 1.6 4 km NW of Cobb, CA
  15. 1.5 10 km NW 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.

For this area

The largest earthquake within 50 km in our catalogue was M 5.0 on 2016-12-14 — it released about 110,000 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.