QuakeIndex

Earthquake · reviewed by a seismologist

M 5.8mww

175 km W of Ferndale, California

· 8.9 km deep · released about 7.6 kilotons of TNT

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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 5.8 (mww)
Depth
8.9 km below the surface
Felt
216 reports · strongest reported intensity V
Measured shaking
intensity III (ShakeMap)
USGS impact alert
green
Tsunami
USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 1608 days ago

This was a moderate earthquake. Shaking at this size can damage poorly built structures close to the epicentre. 216 people have reported feeling it to USGS.

How big was it?

This earthquake released about 7.6 kilotons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 6.8 would have released about 32 times as much.

  1. Ridgecrest, California 2019 M 7.1 89× the energy of this one
  2. Loma Prieta, California 1989 M 6.9 45× the energy of this one
  3. Northridge, California 1994 M 6.7 22× the energy of this one
  4. This earthquake M 5.8 about 7.6 kilotons of TNT
  5. Magna, Utah 2020 M 5.7 this one released 1.4× more
  6. Around the size people start to feel M 3.0 this one released 16,000× 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 40.4556, -126.3332. Map © OpenStreetMap contributors.

Aftershocks so far

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

  1. 3.4 201 km W of Ferndale, California
  2. 3.2 200 km W of Ferndale, California
  3. 2.8 164 km W of Ferndale, California
  4. 2.7 219 km W of Ferndale, California
  5. 2.8 157 km W of Ferndale, California
  6. 2.9 off the coast of Northern California
  7. 2.7 167 km W of Ferndale, California
  8. 3.0 165 km W of Ferndale, California
  9. 3.0 off the coast of Northern California
  10. 2.7 186 km W of Ferndale, California
  11. 2.9 210 km W of Ferndale, California
  12. 2.8 189 km W of Ferndale, California
  13. 3.1 136km W of Petrolia, CA
  14. 2.0 145 km W of Ferndale, California
  15. 4.4 216 km W 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.

For this area

The largest earthquake within 50 km in our catalogue was M 6.6 on 2016-12-08 — it released about 16 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.