QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

9km SE of Lake Pillsbury, CA

· 0.4 km deep · released about 16 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lake County 29 kmMendocino County 49 kmGlenn County 51 kmColusa County 59 kmSonoma County 91 kmTehama County 103 kmNapa County 105 kmSutter County 108 kmYolo County 113 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
0.4 km below the surface
Felt
no reports yet
Nearest
Lake County, 29 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2962 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 39.3462, -122.8885. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lake County, CA 29 km (18 mi) NNW of here earthquakes near Lake County
Mendocino County, CA 49 km (30 mi) E of here earthquakes near Mendocino County
Glenn County, CA 51 km (31 mi) SW of here earthquakes near Glenn County
Colusa County, CA 59 km (37 mi) WNW of here earthquakes near Colusa County
Sonoma County, CA 91 km (57 mi) N of here earthquakes near Sonoma County
Tehama County, CA 103 km (64 mi) SSW of here earthquakes near Tehama County

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

Aftershocks so far

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

  1. 2.0 11km NE of Alder Springs, CA
  2. 1.6 22km NW of Alder Springs, CA
  3. 1.9 7km E of Willits, CA
  4. 2.1 6km WSW of Clearlake, CA
  5. 1.9 8km SSE of Lake Pillsbury, CA
  6. 2.6 9km SE of Redwood Valley, CA
  7. 2.0 8km ESE of Redwood Valley, CA
  8. 2.0 8km ESE of Redwood Valley, CA
  9. 2.4 9km ESE of Willits, CA
  10. 1.8 4km SSE of Lake Pillsbury, CA
  11. 2.5 8km ESE of Willits, CA
  12. 2.0 9km ESE of Willits, CA
  13. 2.6 9km NNE of Brooktrails, CA
  14. 2.1 12km SW of Lake Pillsbury, CA
  15. 1.8 15km NW of Alder Springs, 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 5.1 on 2016-08-10 — it released about 83,000 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.