7km NNW of Hayfork, CA

2021-04-17 05:48 UTC · 32 km deep · released about 67 lb 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: 2021-04-17 05:48 UTC
Magnitude: M 2.2 (md)
Depth: 32 km below the surface
Felt: no reports yet
Nearest: Trinity County, 9 km ENE
Status: Reviewed by a seismologist

USGS · last changed by USGS 1988 days ago · we first saw it 1988 days ago

This was a minor earthquake. Quakes this small are rarely felt and do not cause damage.

How big was it?

This earthquake released about 67 lb of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 3.2 would have released about 32 times as much.

Mineral, Virginia 2011 M 5.8 230,000× the energy of this one
Magna, Utah 2020 M 5.7 160,000× the energy of this one
Around the size people start to feel M 3.0 14× the energy of this one
This earthquake M 2.2 about 67 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

Map loads when it scrolls into view

Epicentre 40.6142, -123.2078. Map © OpenStreetMap contributors.

Nearby places

Place	Distance	Direction
Trinity County, CA	9 km (5 mi)	WSW of here	earthquakes near Trinity County
Humboldt County, CA	61 km (38 mi)	E of here	earthquakes near Humboldt County
Tehama County, CA	99 km (61 mi)	WNW of here	earthquakes near Tehama County
Shasta County, CA	100 km (62 mi)	W of here	earthquakes near Shasta County
Siskiyou County, CA	122 km (76 mi)	SSW of here	earthquakes near Siskiyou County
Glenn County, CA	132 km (82 mi)	NNW of here	earthquakes near Glenn County

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

Aftershocks so far

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

1.5 29km NNE of Redway, CA 09:32 UTC
2.1 25km WNW of Weaverville, CA 11:32 UTC
2.4 14km E of Willow Creek, CA 21:27 UTC
2.3 28km ENE of Willow Creek, CA 05:26 UTC
1.7 31km W of Hayfork, CA 15:07 UTC
1.6 36km E of Rio Dell, CA 22:10 UTC
2.1 26km ESE of Willow Creek, CA 06:13 UTC
2.0 40km SSW of Hayfork, CA 04:35 UTC
2.5 27km WSW of Hayfork, CA 16:52 UTC
1.9 11km NNE of Lewiston, CA 05:35 UTC
1.6 29km W of Hayfork, CA 01:02 UTC
2.1 22km E of Willow Creek, CA 08:59 UTC
2.6 6km NNW of Hayfork, CA 14:44 UTC
2.1 30km WNW of Weaverville, CA 10:02 UTC
2.9 30km WNW of Weaverville, CA 22:58 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 13:08 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 4.5 on 2016-08-28 — it released about 2,500 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.