257 km W of Ferndale, California

2022-12-10 03:17 UTC · 11 km deep · released about 340 tons of TNT

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: 2022-12-10 03:17 UTC
Magnitude: M 4.9 (mww)
Depth: 11 km below the surface
Felt: 10 reports · strongest reported intensity III
Tsunami: USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Status: Reviewed by a seismologist

USGS · last changed by USGS 1317 days ago · we first saw it 1317 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 10 people have reported feeling it to USGS.

How big was it?

This earthquake released about 340 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.9 would have released about 32 times as much.

Northridge, California 1994 M 6.7 500× the energy of this one
Mineral, Virginia 2011 M 5.8 22× the energy of this one
Magna, Utah 2020 M 5.7 16× the energy of this one
This earthquake M 4.9 about 340 tons of TNT
Around the size people start to feel M 3.0 this one released 710× 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

Map loads when it scrolls into view

Epicentre 40.6221, -127.3059. Map © OpenStreetMap contributors.

Aftershocks so far

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

2.6 235 km W of Ferndale, California 21:19 UTC
2.9 266 km W of Ferndale, California 21:13 UTC
2.9 240 km W of Ferndale, California 03:53 UTC
2.7 245 km W of Ferndale, California 16:54 UTC
3.0 287 km W of Ferndale, California 18:42 UTC
2.7 236 km W of Ferndale, California 00:47 UTC
2.8 231 km W of Ferndale, California 07:27 UTC
4.3 244 km W of Ferndale, California 01:41 UTC
3.1 214 km W of Ferndale, California 06:34 UTC
2.9 277 km W of Ferndale, California 03:27 UTC
2.7 245 km W of Ferndale, California 06:25 UTC
2.9 263 km W of Ferndale, California 10:28 UTC
3.2 249 km W of Ferndale, California 02:17 UTC
3.1 234 km W of Ferndale, California 16:33 UTC
2.7 off the coast of Northern California 01:18 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 20:33 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 16 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.