94km W of Trinidad, CA

2021-11-27 07:35 UTC · 24 km deep · released about 22 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: 2021-11-27 07:35 UTC
Magnitude: M 4.1 (mw)
Depth: 24 km below the surface
Felt: 4 reports · strongest reported intensity II
Measured shaking: intensity II (ShakeMap)
USGS impact alert: green
Nearest: Humboldt County, 120 km ESE
Status: Reviewed by a seismologist

USGS · last changed by USGS 1695 days ago · we first saw it 1695 days ago

This was a light earthquake. It is usually felt clearly nearby and can rattle windows and dishes, but damage is uncommon. 4 people have reported feeling it to USGS.

How big was it?

This earthquake released about 22 tons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 5.1 would have released about 32 times as much.

Northridge, California 1994 M 6.7 7,700× the energy of this one
Mineral, Virginia 2011 M 5.8 340× the energy of this one
Magna, Utah 2020 M 5.7 240× the energy of this one
This earthquake M 4.1 about 22 tons of TNT
Around the size people start to feel M 3.0 this one released 46× 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 41.1002, -125.2573. Map © OpenStreetMap contributors.

Nearby places

Place	Distance	Direction
Humboldt County, CA	120 km (75 mi)	WNW of here	earthquakes near Humboldt County
Del Norte County, CA	129 km (80 mi)	WSW of here	earthquakes near Del Norte County

Places and coordinates from the US Census Bureau Gazetteer (2024). Distances are from the epicentre.

Aftershocks so far

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

2.8 67 km WNW of Bayview, CA 19:44 UTC
2.8 103 km WNW of Ferndale, CA 11:15 UTC
2.8 94 km W of Trinidad, CA 21:03 UTC
2.6 81 km WNW of Trinidad, CA 02:14 UTC
4.8 89 km WSW of Crescent City, CA 04:58 UTC
2.9 108 km WNW of Ferndale, CA 01:23 UTC
2.7 65 km WNW of Ferndale, CA 09:35 UTC
2.8 74 km WNW of Bayview, CA 16:41 UTC
3.3 83 km W of Trinidad, CA 00:42 UTC
3.2 55 km WNW of Bayview, CA 12:22 UTC
4.5 74 km WNW of Ferndale, CA 23:18 UTC
2.9 106 km WNW of Trinidad, CA 05:24 UTC
2.9 90 km WNW of Bayview, CA 04:00 UTC
2.8 109 km WNW of Trinidad, CA 18:40 UTC
2.5 93 km WNW of Bayview, CA 11:13 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 16:39 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 5.1 on 2017-07-29 — it released about 29 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.