238 km W of Ferndale, California

This was a small earthquake. Shaking like this is often felt indoors nearby and very rarely causes damage. 1 person has reported feeling it to USGS.

How big was it?

This earthquake released about 1,300 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.1 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 250,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 11,000× the energy of this one
3. Magna, Utah 2020 M 5.7 7,900× the energy of this one
4. This earthquake M 3.1 about 1,300 lb of TNT
5. Around the size people start to feel M 3.0 this one released 1.4× 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.

Where

Epicentre 40.6876, -127.0819. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.5 238 km W of Ferndale, California 19:08 UTC
2. 2.7 262 km W of Ferndale, California 10:11 UTC
3. 2.5 254 km W of Ferndale, California 12:33 UTC
4. 4.0 248 km W of Ferndale, California 18:28 UTC
5. 3.2 258 km W of Ferndale, California 01:59 UTC
6. 2.9 off the coast of Northern California 13:37 UTC
7. 3.0 272 km W of Ferndale, California 12:53 UTC
8. 2.8 256 km W of Ferndale, California 01:08 UTC
9. 2.8 254 km W of Ferndale, California 04:11 UTC
10. 2.4 214 km W of Ferndale, California 01:35 UTC
11. 3.0 262 km W of Indianola, California 12:44 UTC
12. 3.0 275 km W of Ferndale, California 22:29 UTC
13. 2.9 240 km W of Ferndale, California 05:08 UTC
14. 2.7 240 km W of Ferndale, California 04:11 UTC
15. 4.3 265 km W of Ferndale, California 03:30 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 21:48 UTC. 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 5.7 on 2017-09-22 — it released about 7,900 times the energy of this one.

From the QuakeIndex catalogue, built from the USGS FDSN event service.

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.