QuakeIndex

Earthquake · reviewed by a seismologist

M 1.8md

17 km ENE of Hydesville, California

· 22 km deep · released about 15 lb of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Humboldt County 12 kmTrinity County 67 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 1.8 (md)
Depth
22 km below the surface
Felt
no reports yet
Nearest
Humboldt County, 12 km N
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 3516 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 15 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 2.8 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 1,000,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 710,000× the energy of this one
  3. Around the size people start to feel M 3.0 63× the energy of this one
  4. This earthquake M 1.8 about 15 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 40.5962, -123.9035. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Humboldt County, CA 12 km (8 mi) S of here earthquakes near Humboldt County
Trinity County, CA 67 km (42 mi) W of here earthquakes near Trinity County
Siskiyou County, CA 159 km (99 mi) SW of here earthquakes near Siskiyou County

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

Aftershocks so far

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

  1. 2.2 23 km SSW of Ferndale, California
  2. 2.2 14 km WSW of Mad River, California
  3. 1.6 17 km SW of Scotia, California
  4. 2.6 13 km WSW of Ferndale, California
  5. 1.7 23 km WSW of Weott, California
  6. 2.4 22 km WSW of Weott, California
  7. 1.7 13 km WSW of Scotia, California
  8. 1.8 5km NNW of Ferndale, CA
  9. 2.8 9 km SSE of Ferndale, California
  10. 1.7 27 km SW of Scotia, California
  11. 1.8 4 km NNE of Hydesville, California
  12. 1.7 8 km SSE of Ferndale, California
  13. 1.7 21 km SW of Ferndale, California
  14. 2.5 15 km WSW of Scotia, California
  15. 2.3 4 km SW of Scotia, California

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 33,000 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.