QuakeIndex

Earthquake · reviewed by a seismologist

M 3.8mw

16km ESE of Pine Hills, CA

· 21 km deep · released about 7.1 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Humboldt County 3 kmTrinity County 72 kmDel Norte County 117 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 3.8 (mw)
Depth
21 km below the surface
Felt
475 reports · strongest reported intensity IV
Measured shaking
intensity V (ShakeMap)
Nearest
Humboldt County, 3 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2602 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 475 people have reported feeling it to USGS.

How big was it?

This earthquake released about 7.1 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.8 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 24,000× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 1,100× the energy of this one
  3. Magna, Utah 2020 M 5.7 760× the energy of this one
  4. This earthquake M 3.8 about 7.1 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 15× 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 40.6948, -123.9637. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Humboldt County, CA 3 km (2 mi) WSW of here earthquakes near Humboldt County
Trinity County, CA 72 km (45 mi) W of here earthquakes near Trinity County
Del Norte County, CA 117 km (73 mi) S of here earthquakes near Del Norte County

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

Aftershocks so far

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

  1. 1.8 16km ESE of Willow Creek, CA
  2. 1.5 8km NNW of Petrolia, CA
  3. 2.1 9km S of Ferndale, CA
  4. 2.0 35km W of Hayfork, CA
  5. 1.6 9km W of Rio Dell, CA
  6. 1.6 4km NNE of Petrolia, CA
  7. 2.4 6km WNW of Ferndale, CA
  8. 2.4 16km NW of Petrolia, CA
  9. 1.7 5km N of Ferndale, CA
  10. 2.4 4km NNW of Petrolia, CA
  11. 1.7 12km SW of Rio Dell, CA
  12. 2.3 6km ENE of Hydesville, CA
  13. 2.3 15km W of McKinleyville, CA
  14. 2.2 6km W of Rio Dell, CA
  15. 1.8 17km ESE of Pine Hills, 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 4.8 on 2016-07-21 — it released about 35 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.