QuakeIndex

Earthquake · reviewed by a seismologist

M 1.5md

16 km WNW of Ukiah, CA

· -0.5 km deep · released about 6.2 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 27 kmLake County 56 kmSonoma County 84 kmGlenn County 96 kmColusa County 98 kmNapa County 119 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 1.5 (md)
Depth
-0.5 km below the surface
Felt
no reports yet
Nearest
Mendocino County, 27 km NNW
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 424 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 6.2 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.5 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 2,500,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 1,700,000× the energy of this one
  3. Around the size people start to feel M 3.0 150× the energy of this one
  4. This earthquake M 1.5 about 6.2 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 39.1923, -123.3798. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 27 km (17 mi) SSE of here earthquakes near Mendocino County
Lake County, CA 56 km (34 mi) W of here earthquakes near Lake County
Sonoma County, CA 84 km (52 mi) NNW of here earthquakes near Sonoma County
Glenn County, CA 96 km (59 mi) WSW of here earthquakes near Glenn County
Colusa County, CA 98 km (61 mi) W of here earthquakes near Colusa County
Napa County, CA 119 km (74 mi) NW of here earthquakes near Napa County

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

Aftershocks so far

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

  1. 1.6 13 km SSW of Lake Pillsbury, CA
  2. 1.7 14 km NNW of Lake Pillsbury, CA
  3. 1.8 14 km NNE of Point Arena, CA
  4. 1.8 2 km SSE of Navarro Head, CA
  5. 1.7 8 km SSE of Laytonville, CA
  6. 1.6 11 km ESE of Boonville, CA
  7. 1.8 16 km WNW of Lake Pillsbury, CA
  8. 2.1 17 km E of Fort Bragg, CA
  9. 1.7 8 km NNE of Brooktrails, CA
  10. 1.8 11 km N of Upper Lake, CA
  11. 1.7 11 km N of Brooktrails, CA
  12. 1.5 2 km NNW of Lakeport, CA
  13. 1.8 14 km S of Willits, CA
  14. 1.7 11 km N of Brooktrails, CA
  15. 1.7 3 km NW of Redwood Valley, 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 4.4 on 2020-12-06 — it released about 19,000 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.