QuakeIndex

Earthquake · reviewed by a seismologist

M 2.8md

26km W of Humboldt Hill, CA

· 25 km deep · released about 450 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Humboldt County 48 kmTrinity County 117 kmDel Norte County 120 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 2.8 (md)
Depth
25 km below the surface
Felt
2 reports · strongest reported intensity I
Nearest
Humboldt County, 48 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2213 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 2 people have reported feeling it to USGS.

How big was it?

This earthquake released about 450 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 34,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 24,000× the energy of this one
  3. Around the size people start to feel M 3.0 2.1× the energy of this one
  4. This earthquake M 2.8 about 450 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 40.7447, -124.4958. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Humboldt County, CA 48 km (30 mi) W of here earthquakes near Humboldt County
Trinity County, CA 117 km (73 mi) W of here earthquakes near Trinity County
Del Norte County, CA 120 km (74 mi) SSW 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

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

  1. 2.1 46km WNW of Petrolia, CA
  2. 2.3 20km W of Humboldt Hill, CA
  3. 3.0 19km WNW of Humboldt Hill, CA
  4. 2.1 23km W of Petrolia, CA
  5. 2.1 26km WNW of Petrolia, CA
  6. 2.1 25km W of Petrolia, CA
  7. 2.3 11km SSW of Ferndale, CA
  8. 2.0 12km WNW of Petrolia, CA
  9. 1.7 20km WSW of Ferndale, CA
  10. 2.9 68km WNW of Ferndale, CA
  11. 2.0 11km SSW of Ferndale, CA
  12. 1.6 16km WNW of Petrolia, CA
  13. 2.2 21km WNW of Petrolia, CA
  14. 2.2 57km WNW of Bayview, CA
  15. 1.7 14km 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 5.2 on 2020-03-18 — it released about 4,400 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.