2024 Offshore Cape Mendocino, California Earthquake

2024-12-05 18:44 UTC · 10 km deep · released about 480 kilotons 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: 2024-12-05 18:44 UTC
Magnitude: M 7.0 (mw)
Depth: 10 km below the surface
Felt: 16883 reports · strongest reported intensity VIII
Measured shaking: intensity VIII (ShakeMap)
USGS impact alert: yellow
Tsunami: USGS flagged this event for tsunami evaluation. Follow tsunami.gov for official messages.
Nearest: Humboldt County, 100 km ENE
Status: Reviewed by a seismologist

USGS · last changed by USGS 72 days ago · we first saw it 72 days ago

This was a major earthquake. Serious damage is likely near the epicentre. Follow official information from USGS and local authorities. 16883 people have reported feeling it to USGS.

How big was it?

This earthquake released about 480 kilotons of TNT. Magnitude is logarithmic: each whole step up releases about 32 times more energy, so a magnitude 8.0 would have released about 32 times as much.

Tōhoku, Japan 2011 M 9.1 1,400× the energy of this one
San Francisco 1906 M 7.9 22× the energy of this one
Ridgecrest, California 2019 M 7.1 1.4× the energy of this one
This earthquake M 7.0 about 480 kilotons of TNT
Loma Prieta, California 1989 M 6.9 this one released 1.4× more
Northridge, California 1994 M 6.7 this one released 2.8× 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 40.3740, -125.0217. Map © OpenStreetMap contributors.

Nearby places

Place	Distance	Direction
Humboldt County, CA	100 km (62 mi)	WSW of here	earthquakes near Humboldt County

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

Aftershocks so far

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

2.0 43 km W of Petrolia, CA 21:33 UTC
2.9 30 km W of Petrolia, CA 21:31 UTC
2.1 46 km WNW of Petrolia, CA 21:28 UTC
2.8 42 km WNW of Petrolia, CA 21:16 UTC
2.6 46 km W of Ferndale, CA 21:11 UTC
2.6 54 km WNW of Petrolia, CA 21:11 UTC
3.4 62 km WNW of Petrolia, CA 21:08 UTC
3.2 114 km WSW of Ferndale, California 21:08 UTC
3.2 49 km WNW of Petrolia, CA 21:07 UTC
2.2 18 km W of Petrolia, CA 21:05 UTC
2.7 60 km WNW of Petrolia, CA 21:04 UTC
2.8 79 km W of Ferndale, CA 21:02 UTC
2.8 56 km WNW of Petrolia, CA 21:01 UTC
2.2 47 km WNW of Petrolia, CA 20:58 UTC
2.5 44 km WNW of Petrolia, CA 20:56 UTC

Counted from the QuakeIndex database, which ingests the USGS feed every 30 seconds · as of 16:31 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 5.8 on 2020-03-09.

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.