QuakeIndex

Earthquake · reviewed by a seismologist

M 2.9md

Earthquake near Ferndale, CA

No earthquake was likely felt in Ferndale in the 24 hours to 11:02 pm PST (07:02 UTC). The last one was M 5.0, 113 km (70 mi) W, at 8:56 pm PST on 4 November 2026, estimated intensity III (weak) in town; 145 felt reports to USGS. Every earthquake near Ferndale

This page: a magnitude 2.9 earthquake was recorded 28 km (18 mi) west of Ferndale, CA, at 2:45 am PST on 7 February 2020 (10:45 UTC), 25 km deep.

USGS: 28km W of Ferndale, CA

2:45 am PST, Feb 7, 2020 · · 25 km deep · released about 630 lb of TNT

10 km30 km60 km120 km N Humboldt County 58 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
2:45 am PST on 7 February 2020 ()
Where
28 km (18 mi) west of Ferndale, CA · earthquakes near Ferndale
Magnitude
M 2.9 (md)
Depth
25 km below the surface
Felt
no reports yet
Nearest
Humboldt County, 58 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2391 days ago

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage.

At this magnitude and depth, people at rest would likely notice it out to about 18 km (11 mi) from the epicentre. In Ferndale, 28 km away, the estimate is intensity II (weak). Estimated from magnitude, depth and distance with the intensity equation USGS Did You Feel It? uses; felt reports, where there are any, are the measurement.

How big was it?

This earthquake released about 630 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.9 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 24,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 17,000× the energy of this one
  3. Around the size people start to feel M 3.0 1.5× the energy of this one
  4. This earthquake M 2.9 about 630 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.

For this area

The largest earthquake within 50 km since 2016 was M 5.6 on 2019-06-23 — about 11,000 times the energy of this one.

Before 2016, the USGS record lists 45 earthquakes of M5 or more within 50 km; the five largest:

  1. 7.2 The 1992 Petrolia, California Earthquake · 44 km SE of this epicentre
  2. 6.6 32 km SW of Ferndale, California · 26 km S of this epicentre
  3. 6.5 The 1932 Eureka, California Earthquake · 29 km ENE of this epicentre
  4. 6.5 30 km WSW of Ferndale, California · 20 km S of this epicentre
  5. 6.5 The 2010 Eureka, California Earthquake · 9 km WNW of this epicentre

Since 2016: the QuakeIndex catalogue (US, M1.5+), built from the USGS FDSN event service. Before 2016: USGS ComCat, M5+ from 1900. Distances are between epicentres. This is the record, not a forecast.

Where

Epicentre 40.6128, -124.5970. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Humboldt County, CA 58 km (36 mi) E earthquakes near Humboldt County

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

Aftershocks so far

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

  1. 2.3 43km WNW of Petrolia, CA
  2. 3.5 33km W of Petrolia, CA
  3. 4.8 47km WNW of Petrolia, CA
  4. 1.6 12km S of Ferndale, CA
  5. 2.1 12km WSW of Rio Dell, CA
  6. 1.9 13km WSW of Petrolia, CA
  7. 1.8 10km N of Petrolia, CA
  8. 2.2 13km WNW of Petrolia, CA
  9. 1.7 7km NE of Petrolia, CA
  10. 2.3 36km WNW of Petrolia, CA
  11. 1.9 22km WSW of Ferndale, CA
  12. 2.4 34km W of Petrolia, CA
  13. 1.9 11km W of Petrolia, CA
  14. 2.2 42km WNW of Petrolia, CA
  15. 1.7 23km NW of Petrolia, 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.

On USGS

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