QuakeIndex

Earthquake · reviewed by a seismologist

M 2.1md

17km ESE of Pine Hills, CA

· 25 km deep · released about 46 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Humboldt County 3 kmTrinity County 71 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 2.1 (md)
Depth
25 km below the surface
Felt
no reports yet
Nearest
Humboldt County, 3 km ENE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1528 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 46 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.1 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 330,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 230,000× the energy of this one
  3. Around the size people start to feel M 3.0 21× the energy of this one
  4. This earthquake M 2.1 about 46 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 40.6937, -123.9583. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Humboldt County, CA 3 km (2 mi) WSW of here earthquakes near Humboldt County
Trinity County, CA 71 km (44 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

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

  1. 2.7 7km N of Petrolia, CA
  2. 1.9 18km ENE of Hydesville, CA
  3. 2.4 9km N of Petrolia, CA
  4. 2.0 7km SE of Rio Dell, CA
  5. 2.1 21km WNW of Ferndale, CA
  6. 1.7 10km SSW of Ferndale, CA
  7. 1.6 31km WSW of Hayfork, CA
  8. 1.7 4km WSW of Humboldt Hill, CA
  9. 1.8 20km SSE of Willow Creek, CA
  10. 1.9 4km SSW of Humboldt Hill, CA
  11. 1.8 11km SSW of Ferndale, CA
  12. 2.0 17km ENE of Hydesville, CA
  13. 2.3 16km WSW of Ferndale, CA
  14. 1.5 29km NNE of Redway, CA
  15. 2.1 8km SSE of Ferndale, 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 6.2 on 2021-12-20 — it released about 1,300,000 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.