256 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 480 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.8 would have released about 32 times as much.

1. Mineral, Virginia 2011 M 5.8 32,000× the energy of this one
2. Magna, Utah 2020 M 5.7 22,000× the energy of this one
3. Around the size people start to feel M 3.0 2× the energy of this one
4. This earthquake M 2.8 about 480 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.

Where

Epicentre 40.5664, -127.2876. Map © OpenStreetMap contributors.

Aftershocks so far

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

1. 3.2 249 km W of Ferndale, California 02:17 UTC
2. 3.1 234 km W of Ferndale, California 16:33 UTC
3. 2.9 250 km W of Ferndale, California 13:33 UTC
4. 2.9 253 km W of Ferndale, California 13:28 UTC
5. 2.7 210 km W of Ferndale, California 14:30 UTC
6. 2.6 277 km W of Ferndale, California 05:56 UTC
7. 2.9 238 km W of Ferndale, California 22:47 UTC
8. 3.3 235 km W of Ferndale, California 08:17 UTC
9. 2.9 237 km W of Ferndale, California 22:33 UTC
10. 2.8 251 km W of Ferndale, California 02:11 UTC
11. 3.2 245 km W of Ferndale, California 16:55 UTC
12. 3.1 245 km W of Ferndale, California 11:37 UTC
13. 3.2 222 km W of Ferndale, California 20:10 UTC
14. 3.4 258 km W of Ferndale, California 00:01 UTC
15. 3.4 262 km W of Ferndale, California 07:47 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 22:31 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 22,000 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.