QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

23km ESE of Rio Dell, CA

· 31 km deep · released about 780 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Humboldt County 33 kmTrinity County 68 kmMendocino County 115 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 2.9 (md)
Depth
31 km below the surface
Felt
4 reports · strongest reported intensity III
Nearest
Humboldt County, 33 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2073 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 4 people have reported feeling it to USGS.

How big was it?

This earthquake released about 780 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 19,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 14,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.2× the energy of this one
  4. This earthquake M 2.9 about 780 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 40.4130, -123.8637. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Humboldt County, CA 33 km (21 mi) S of here earthquakes near Humboldt County
Trinity County, CA 68 km (43 mi) WSW of here earthquakes near Trinity County
Mendocino County, CA 115 km (71 mi) NNW of here earthquakes near Mendocino 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. 4.0 20km ENE of Redway, CA
  2. 1.9 10km S of Petrolia, CA
  3. 1.8 35km S of Willow Creek, CA
  4. 1.9 29km NE of Redway, CA
  5. 2.5 14km SE of Petrolia, CA
  6. 1.8 27km SSE of Blue Lake, CA
  7. 2.0 19km NE of Redway, CA
  8. 1.6 14km SW of Ferndale, CA
  9. 2.2 8km SSE of Ferndale, CA
  10. 1.6 7km SSW of Petrolia, CA
  11. 2.1 11km SSE of Redway, CA
  12. 2.1 9km N of Petrolia, CA
  13. 2.4 34km E of Hydesville, CA
  14. 2.2 34km E of Hydesville, CA
  15. 2.0 6km S of Petrolia, 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 5.6 on 2019-06-23 — it released about 9,100 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.