QuakeIndex

Earthquake · reviewed by a seismologist

M 4.4mw

46 km SW of Ferndale, California

· 15 km deep · released about 69 tons of TNT

Felt it? Tell USGS Check my area
10 km30 km60 km120 km N Humboldt County 78 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 4.4 (mw)
Depth
15 km below the surface
Felt
265 reports · strongest reported intensity IV
Measured shaking
intensity IV (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest
Humboldt County, 78 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2321 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 265 people have reported feeling it to USGS.

How big was it?

This earthquake released about 69 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.4 would have released about 32 times as much.

  1. Northridge, California 1994 M 6.7 2,500× the energy of this one
  2. Mineral, Virginia 2011 M 5.8 110× the energy of this one
  3. Magna, Utah 2020 M 5.7 78× the energy of this one
  4. This earthquake M 4.4 about 69 tons of TNT
  5. Around the size people start to feel M 3.0 this one released 140× 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 40.3083, -124.6872. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Humboldt County, CA 78 km (49 mi) SW of here earthquakes near Humboldt County
Mendocino County, CA 144 km (90 mi) NW of here earthquakes near Mendocino County

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

Aftershocks so far

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

  1. 2.2 8 km WSW of Rio Dell, California
  2. 2.4 34 km SW of Ferndale, California
  3. 3.2 28 km SW of Ferndale, California
  4. 2.0 29 km SW of Ferndale, California
  5. 2.2 35 km SW of Ferndale, California
  6. 2.2 32 km SW of Ferndale, California
  7. 2.5 50 km SW of Ferndale, California
  8. 1.9 24 km SW of Scotia, California
  9. 2.7 74 km WSW of Ferndale, California
  10. 1.9 8 km W of Rio Dell, California
  11. 2.6 35 km SW of Ferndale, California
  12. 2.5 36 km SSW of Ferndale, California
  13. 2.2 48 km W of Ferndale, California
  14. 2.1 23 km SW of Scotia, California
  15. 2.1 6 km S of Ferndale, 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.

On USGS

QuakeIndex does not issue warnings. For earthquake early warning see ShakeAlert.