QuakeIndex

Earthquake · reviewed by a seismologist

M 5.7ml

29km W of Petrolia, CA

· 17 km deep · released about 4.5 kilotons of TNT

10 km30 km60 km120 km N Humboldt County 75 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 5.7 (ml)
Depth
17 km below the surface
Felt
no reports yet
Measured shaking
intensity V (ShakeMap)
USGS impact alert
green
Nearest
Humboldt County, 75 km NE
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 279 days ago

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre.

How big was it?

This earthquake released about 4.5 kilotons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.7 would have released about 32 times as much.

  1. Loma Prieta, California 1989 M 6.9 75× the energy of this one
  2. Northridge, California 1994 M 6.7 38× the energy of this one
  3. Mineral, Virginia 2011 M 5.8 1.7× the energy of this one
  4. This earthquake M 5.7 about 4.5 kilotons of TNT
  5. Around the size people start to feel M 3.0 this one released 9,400× 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 40.2978, -124.6260. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection
Humboldt County, CA 75 km (46 mi) SW of here earthquakes near Humboldt County
Mendocino County, CA 139 km (87 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

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

  1. 3.9 6km NE of Petrolia, CA
  2. 3.3 18km SW of Ferndale, CA
  3. 2.2 12km SSW of Ferndale, CA
  4. 2.3 12km SW of Rio Dell, CA
  5. 2.4 11km SSW of Ferndale, CA
  6. 2.4 11km NNE of Petrolia, CA
  7. 2.4 14km NNW of Petrolia, CA
  8. 3.2 11km NNE of Petrolia, CA
  9. 2.0 4km ENE of Petrolia, CA
  10. 2.6 12km SSW of Ferndale, CA
  11. 2.7 15km SW of Ferndale, CA
  12. 2.6 14km N of Petrolia, CA
  13. 3.3 13km SSW of Ferndale, CA
  14. 2.4 12km S of Ferndale, CA
  15. 2.3 8km SSW 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 5.8 on 2020-03-09 — it released about 1.5 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.