QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

6 km W of Middletown, California

· 0.2 km deep · released about 16 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Sonoma County 33 kmLake County 40 kmNapa County 42 kmColusa County 61 kmYolo County 69 kmMarin County 78 kmSolano County 85 kmSutter County 91 kmGlenn County 98 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 1.8 (md)
Depth
0.2 km below the surface
Felt
no reports yet
Nearest
Sonoma County, 33 km SW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3516 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 16 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 5.8 970,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 680,000× the energy of this one
  3. Around the size people start to feel M 3.0 61× the energy of this one
  4. This earthquake M 1.8 about 16 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 38.7527, -122.6882. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Sonoma County, CA 33 km (20 mi) NE of here earthquakes near Sonoma County
Lake County, CA 40 km (25 mi) S of here earthquakes near Lake County
Napa County, CA 42 km (26 mi) NW of here earthquakes near Napa County
Colusa County, CA 61 km (38 mi) SW of here earthquakes near Colusa County
Yolo County, CA 69 km (43 mi) W of here earthquakes near Yolo County
Marin County, CA 78 km (49 mi) N of here earthquakes near Marin 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. 1.8 9 km W of Cobb, California
  2. 1.6 4 km S of Cobb, California
  3. 1.8 9 km W of Cobb, California
  4. 1.9 8 km W of Cobb, California
  5. 1.7 7 km W of Cobb, California
  6. 2.0 7 km S of Cobb, California
  7. 1.5 9 km NE of Cloverdale, California
  8. 2.3 3 km ENE of Lower Lake, California
  9. 1.9 8 km W of Cobb, California
  10. 1.6 4 km SW of Cobb, California
  11. 1.7 4 km W of Cobb, California
  12. 1.6 9 km WNW of Cobb, California
  13. 1.8 5 km SW of Cobb, California
  14. 1.6 12 km N of Cazadero, California
  15. 1.6 5 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.