QuakeIndex

Earthquake · reviewed by a seismologist

M 2.6md

64km WNW of Ferndale, CA

Yes. A magnitude 2.6 earthquake was recorded 64km WNW of Ferndale, CA, at 4:05 pm PDT on 25 August 2018 (23:05 UTC), 26 km deep.

· 26 km deep · released about 220 lb of TNT

10 km30 km60 km120 km N Humboldt County 89 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 2.6 (md)
Depth
26 km below the surface
Felt
no reports yet
Nearest
Humboldt County, 89 km E
Status
Reviewed by a seismologist

USGS · last changed by USGS · we first saw it 2999 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 it was probably too small to be felt, even directly above it. 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 220 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.6 would have released about 32 times as much.

  1. Mineral, Virginia 2011 M 5.8 70,000× the energy of this one
  2. Magna, Utah 2020 M 5.7 50,000× the energy of this one
  3. Around the size people start to feel M 3.0 4.4× the energy of this one
  4. This earthquake M 2.6 about 220 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 5.1 on 2017-07-29 — about 5,800 times the energy of this one.

Before 2016, the USGS record lists 21 earthquakes of M5 or more within 50 km; the five largest:

  1. 6.5 30 km WSW of Ferndale, California · 50 km SE of this epicentre
  2. 6.5 The 2010 Eureka, California Earthquake · 27 km ESE of this epicentre
  3. 6.4 Northwest of Eureka, California · 50 km NE of this epicentre
  4. 6.3 67 km W of Trinidad, California · 32 km N of this epicentre
  5. 6.0 near the coast of Northern California · 16 km E 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 40.7467, -124.9862. Map © OpenStreetMap contributors.

Nearby places

PlaceDistanceDirection from the epicentre
Humboldt County, CA 89 km (56 mi) E earthquakes near Humboldt County
Del Norte County, CA 140 km (87 mi) NE earthquakes near Del Norte County

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

Aftershocks so far

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

  1. 2.7 37km WNW of Petrolia, CA
  2. 3.0 42km W of Petrolia, CA
  3. 4.3 62km W of Petrolia, CA
  4. 2.6 36km W of Petrolia, CA
  5. 2.6 40km WNW of Petrolia, CA
  6. 2.6 29km W of Ferndale, CA
  7. 2.9 44km WNW of Bayview, CA
  8. 2.5 30km WNW of Petrolia, CA
  9. 2.6 38km W of Petrolia, CA
  10. 2.9 81km W of Petrolia, CA
  11. 2.6 31km WNW of Petrolia, CA
  12. 2.8 49km W of Ferndale, CA
  13. 2.9 47km W of Ferndale, CA
  14. 3.3 68km W of Petrolia, CA
  15. 2.6 51km W 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.

On USGS

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