Earthquake near Ferndale, CA

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 63 km (39 mi) from the epicentre. In Ferndale, 23 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.

Likely felt in: Ferndale 23 km, intensity II · Fortuna 33 km, intensity II · Rio Dell 34 km, intensity II · Humboldt Hill 38 km, intensity II · Eureka 46 km, intensity II. Estimated for each town centre; each link is that town's own record.

How big was it?

This earthquake released about 3.5 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.6 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 48,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 2,100× the energy of this one
3. Magna, Utah 2020 M 5.7 1,500× the energy of this one
4. This earthquake M 3.6 about 3.5 tons of TNT
5. Around the size people start to feel M 3.0 this one released 7.4× 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.

For this area

The largest earthquake within 50 km since 2016 was M 7.0 on 2024-12-05 — about 130,000 times the energy of this one.

Before 2016, the USGS record lists 46 earthquakes of M5 or more within 50 km; the five largest:

1. 7.2 The 1992 Petrolia, California Earthquake · 29 km SE of this epicentre Apr 25, 1992
2. 6.6 32 km SW of Ferndale, California · 12 km SSW of this epicentre Apr 26, 1992
3. 6.5 The 1932 Eureka, California Earthquake · 33 km NE of this epicentre Jun 6, 1932
4. 6.5 30 km WSW of Ferndale, California · 7 km SW of this epicentre Apr 26, 1992
5. 6.5 The 2010 Eureka, California Earthquake · 24 km NW of this epicentre Jan 10, 2010

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 40.4815, -124.5108. Map © OpenStreetMap contributors.

Nearby places

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. 2.0 31 km W of Petrolia, CA 22:36 UTC
2. 1.8 24 km W of Petrolia, CA 22:30 UTC
3. 2.3 64 km WNW of Ferndale, CA 22:30 UTC
4. 2.0 45 km W of Petrolia, CA 22:28 UTC
5. 2.8 49 km WNW of Petrolia, CA 22:27 UTC
6. 2.5 23 km W of Petrolia, CA 22:22 UTC
7. 2.5 54 km WNW of Petrolia, CA 22:20 UTC
8. 2.5 46 km WNW of Petrolia, CA 22:20 UTC
9. 1.8 24 km W of Petrolia, CA 22:19 UTC
10. 2.0 40 km W of Petrolia, CA 22:19 UTC
11. 2.7 26 km W of Petrolia, CA 22:14 UTC
12. 2.0 33 km W of Ferndale, CA 22:14 UTC
13. 2.3 46 km W of Petrolia, CA 22:14 UTC
14. 2.4 55 km WNW of Petrolia, CA 22:12 UTC
15. 2.1 20 km W of Petrolia, CA 22:10 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 12:13 UTC. QuakeIndex does not forecast aftershocks. When USGS issues an operational aftershock forecast it appears on the USGS event page.

On USGS

• The official USGS event page — the source of record for every value above
• Did you feel it? Report it to USGS — reports go to USGS, not to us
• ShakeMap for this event, when USGS has produced one

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