A significant earthquake with a magnitude of 4.1 struck near the town of Cobb in Lake County, California, on December 5, 2024, at approximately 10:47 a.m. This event occurred just minutes after a powerful 7.0-magnitude earthquake hit off the Northern California coast, prompting a tsunami warning for parts of the state and Oregon 1 2.
Earthquake Details and Initial Response
The initial report indicated the earthquake had a magnitude of 5.8, approximately 5.6 miles west northwest of Cobb, with a depth of 0.6 miles 1. However, the U.S. Geological Survey (USGS) later revised the magnitude to 4.1 1. The epicenter was located at coordinates (38.8456649780273, -122.752166748047), with a depth of 1.07000005245209 kilometers 5.
Tsunami Warning and Emergency Measures
The larger 7.0-magnitude earthquake triggered a tsunami warning for a long stretch of the California coast, extending north into Oregon and south of Monterey County 1 2. The National Weather Service issued a tsunami warning with an expected arrival time in the Bay Area at 12:10 p.m., but this warning was subsequently canceled 1 2. Coastal residents along the north coast were advised to move to higher ground due to the tsunami warning, with evacuation orders issued by local authorities 2.
Infrastructure Damage and Humanitarian Challenges
Despite the significant magnitude of the 7.0 earthquake, there have been no major reports of damage or injuries as of Thursday afternoon 3. However, residents in affected areas reported intense shaking, with objects knocked off shelves and glass items shattered on the ground 3. In Ferndale, a bed-and-breakfast innkeeper described the scene as "insane," with fireplaces flying forward and significant items displaced 3. Local businesses, such as the Petrolia General Store, experienced significant shaking, with objects knocked off shelves and some structural damage reported 3.
Emergency Response and Humanitarian Efforts
Emergency officials were quick to respond to the situation. The California Office of Emergency Services operations center was activated, and Governor Gavin Newsom issued an emergency proclamation in response to the incident 2. The Bay Area Rapid Transit service through the Transbay Tube was halted temporarily but resumed normal operations by noon, with riders expected to experience delays 2 3. Firefighters scanned beaches and ordered people to evacuate, while residents gathered at waterfronts to watch the waves roll in 3.
Community Reactions and Future Preparations
Residents in affected areas expressed relief that the tsunami warning was canceled, but acknowledged the significant impact of the earthquakes on their daily lives. "It was a big earthquake," said Kaitlin Graves, an employee at Petrolia General Store. "It was a lot of up-and-down shaking" 3. Local authorities emphasized the importance of preparedness for future earthquakes, highlighting the need for robust emergency systems and community resilience.