175 km W of Ferndale, California

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

How big was it?

This earthquake released about 1,900 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 4.2 would have released about 32 times as much.

1. Northridge, California 1994 M 6.7 180,000× the energy of this one
2. Mineral, Virginia 2011 M 5.8 7,900× the energy of this one
3. Magna, Utah 2020 M 5.7 5,600× the energy of this one
4. This earthquake M 3.2 about 1,900 lb of TNT
5. Around the size people start to feel M 3.0 this one released 2× 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 40.8185, -126.3132. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 2.7 157 km W of Ferndale, California 16:14 UTC
2. 3.8 163 km W of Ferndale, California 04:39 UTC
3. 2.6 154 km W of Ferndale, California 16:47 UTC
4. 2.5 135 km W of Ferndale, California 03:39 UTC
5. 3.2 155 km W of Ferndale, California 20:11 UTC
6. 2.7 154 km W of Ferndale, California 05:17 UTC
7. 2.8 163 km W of Ferndale, California 18:34 UTC
8. 2.5 163 km WNW of Indianola, California 01:54 UTC
9. 2.6 190 km W of Ferndale, California 05:48 UTC
10. 2.7 169 km W of Ferndale, California 22:38 UTC
11. 2.9 165 km W of Ferndale, California 12:07 UTC
12. 2.3 160 km W of Ferndale, California 21:47 UTC
13. 2.6 155 km W of Ferndale, California 19:21 UTC
14. 2.6 191 km W of Ferndale, California 06:40 UTC
15. 2.6 150 km W of Ferndale, California 03:49 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 16:18 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 6.6 on 2016-12-08 — it released about 130,000 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.