Location:

M 7.0 2024 Offshore Cape Mendocino, California Earthquake

Magnitude:

7.0

Time:

5 Dec 2024 18:44:21

Depth:

10.0

There are 10 swarms found nearby.

2002

S20020504.1(48.3km)

4 May

2 days 13 hours

44 earthquakes

2010

S20100110.2(19.7km)

10 Jan

2 days 2 hours

30 earthquakes

2014

S20140311.1(34.8km)

10 Mar

2 days 2 hours

31 earthquakes

2015

S20150129.1(62.5km)

28 Jan

20 hours

25 earthquakes

2021

S20211220.1(60.9km)

20 Dec

4 days 3 hours

113 earthquakes

2022

S20221220.1(60.3km)

20 Dec

6 days 3 hours

165 earthquakes

S20221220.2(84.7km)

20 Dec

1 day 18 hours

56 earthquakes

2024

S20241205.1(39.3km)

5 Dec

8 days 15 hours

194 earthquakes

S20241205.2(47.3km)

5 Dec

1 day 21 hours

108 earthquakes

S20241206.1(7.5km)

5 Dec

5 days 23 hours

65 earthquakes

AI-generated article — for informational and entertainment purposes only. May contain inaccuracies. Full disclaimerFound an error?

2024 M7.0 Offshore Cape Mendocino Earthquake: Geological Context and Regional History

On December 5, 2024, at 18:44 UTC, a magnitude 7.0 earthquake struck offshore Cape Mendocino, California, at a depth of 10.0 km. The event originated directly within the Mendocino Triple Junction, a tectonically complex zone where the Pacific, North American, and Juan de Fuca plates converge. This earthquake represents the strongest event in the region since 2000.

Cape Mendocino lies at the southern termination of the Cascadia Subduction Zone and the northern end of the San Andreas Fault system. The triple junction accommodates rapid plate motion through a combination of strike-slip faulting along the Mendocino Fault and thrust faulting associated with the Gorda plate. The area experiences frequent seismicity due to the transition from subduction to transform tectonics, producing both deep intraslab events and shallow crustal ruptures.

Historical records document significant earthquakes near Cape Mendocino, including the 1992 magnitude 7.2 event that generated a local tsunami and caused extensive damage along the northern California coast. The 2024 earthquake shares similar characteristics with prior events in the vicinity, occurring along active structures that accommodate Pacific-North American plate boundary deformation. The Mendocino Fault, a major right-lateral strike-slip feature, and nearby thrust faults within the accretionary wedge contribute to the region's elevated seismic hazard.

Geological studies of the area highlight thick sedimentary sequences overlying the subducting slab and fractured basement rocks that influence rupture propagation. The shallow focal depth of 10 km placed the event within the brittle upper crust, where accumulated strain from plate motion is periodically released. Coastal geomorphology, including uplifted marine terraces, reflects long-term deformation driven by these tectonic processes.

The 2024 earthquake underscores the persistent seismic risk along California's North Coast. Monitoring networks operated by the U.S. Geological Survey and regional partners continue to track aftershock sequences and crustal deformation to refine hazard assessments for the Mendocino Triple Junction.

References

U.S. Geological Survey Earthquake Hazards Program event data
California Geological Survey regional fault and seismicity reports
Tectonic summaries of the Mendocino Triple Junction from peer-reviewed geophysical literature