QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

2km N of Lake Pillsbury, CA

· 6.5 km deep · released about 17 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Lake County 39 kmMendocino County 42 kmGlenn County 52 kmColusa County 67 kmTehama County 100 kmSonoma County 100 kmNapa County 115 kmSutter County 116 kmButte 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 1.8 (md)
Depth
6.5 km below the surface
Felt
no reports yet
Nearest
Lake County, 39 km SSE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1997 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 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.

Where

Epicentre 39.4222, -122.9553. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Lake County, CA 39 km (24 mi) NNW of here earthquakes near Lake County
Mendocino County, CA 42 km (26 mi) E of here earthquakes near Mendocino County
Glenn County, CA 52 km (32 mi) WSW of here earthquakes near Glenn County
Colusa County, CA 67 km (42 mi) WNW of here earthquakes near Colusa County
Tehama County, CA 100 km (62 mi) SW of here earthquakes near Tehama County
Sonoma County, CA 100 km (62 mi) N of here earthquakes near Sonoma County

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

Aftershocks so far

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

  1. 1.8 16km NE of Upper Lake, CA
  2. 2.0 11km W of Alder Springs, CA
  3. 1.9 14km SE of Lake Pillsbury, CA
  4. 1.5 10km SE of Willits, CA
  5. 1.9 10km SE of Willits, CA
  6. 1.9 5km SSE of Redwood Valley, CA
  7. 1.9 6km SSE of Redwood Valley, CA
  8. 1.9 8km NNW of Redwood Valley, CA
  9. 2.0 12km WNW of Lake Pillsbury, CA
  10. 1.9 4km NNW of Lake Pillsbury, CA
  11. 1.8 6km E of Willits, CA
  12. 1.8 9km NNW of Redwood Valley, CA
  13. 2.2 7km E of Willits, CA
  14. 1.7 10km SW of Ukiah, CA
  15. 1.6 7km E of Willits, 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 75,000 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.