QuakeIndex

Earthquake · reviewed by a seismologist

M 4.2mw

9 km NNE of Lake Pillsbury, CA

· 11 km deep · released about 28 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Mendocino County 43 kmLake County 46 kmGlenn County 48 kmColusa County 70 kmTehama County 93 kmSonoma County 107 kmButte County 117 kmSutter County 118 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 4.2 (mw)
Depth
11 km below the surface
Felt
116 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Nearest
Mendocino County, 43 km W
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 95 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 116 people have reported feeling it to USGS.

How big was it?

This earthquake released about 28 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.2 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 6,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 270× the energy of this one
  3. Magna, Utah 2020 M 5.7 190× the energy of this one
  4. This earthquake M 4.2 about 28 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 59× more

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 39.4915, -122.9483. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Mendocino County, CA 43 km (27 mi) E of here earthquakes near Mendocino County
Lake County, CA 46 km (29 mi) NNW of here earthquakes near Lake County
Glenn County, CA 48 km (30 mi) WSW of here earthquakes near Glenn County
Colusa County, CA 70 km (44 mi) WNW of here earthquakes near Colusa County
Tehama County, CA 93 km (58 mi) SW of here earthquakes near Tehama County
Sonoma County, CA 107 km (67 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

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

  1. 1.7 6 km E of Redwood Valley, CA
  2. 1.6 15 km SSE of Laytonville, CA
  3. 2.0 0 km NNW of Willits, CA
  4. 1.9 1 km NNW of Willits, CA
  5. 2.1 1 km NNW of Willits, CA
  6. 2.7 1 km NNW of Willits, CA
  7. 3.6 1 km NNW of Willits, CA
  8. 2.1 6 km SSE of Lake Pillsbury, CA
  9. 1.5 8 km W of Redwood Valley, CA
  10. 1.8 10 km NNE of Brooktrails, CA
  11. 1.8 9 km NNW of Redwood Valley, CA
  12. 1.7 10 km SSE of Lake Pillsbury, CA
  13. 2.4 10 km NNW of Redwood Valley, CA
  14. 1.5 10 km SSE of Willits, CA
  15. 1.7 5 km NNE of Lake Pillsbury, 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 23 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.