On the night of December 30, 2025, residents across Northern California were startled by a moderate earthquake that rippled through Lassen County, shaking homes and nerves but ultimately leaving the region largely unscathed. According to preliminary seismic reports from the U.S. Geological Survey (USGS), the main quake struck at 9:49 p.m., registering a magnitude of 4.9 after initial readings pegged it at 5.3. The epicenter was pinpointed roughly 9 to 10 miles north-northeast of Susanville, with the tremor originating at a shallow depth of about 3 miles (approximately 5 kilometers) beneath the surface.
The quake was felt widely, with the USGS receiving a flood of responses from the public. As reported by the USGS and cited by multiple outlets, more than 1,200 people submitted felt reports through the agency’s online "Did You Feel It?" form, describing sensations ranging from a mild jolt to moderate, sustained shaking. Residents in cities as distant as Sacramento, Camino, Pollock Pines, South Lake Tahoe, and Malin reported feeling the tremor, underscoring just how far its effects reached.
Despite the widespread awareness, local authorities moved quickly to reassure the public. The Susanville Police Department stated there were no immediate reports of injuries or significant damage, and police dispatcher Tracy Mattern characterized the event as “just kind of a short rumble.” Still, officials urged residents to remain alert for potential aftershocks and to review earthquake safety procedures, a prudent reminder given California’s seismic history.
Earthquake preparedness is second nature in California, but every tremor brings a fresh wave of anxiety and a flurry of questions. What caused this latest quake? According to the USGS, the area around Susanville sits east of California’s major fault lines, though minor faults like Hat Creek do run nearby. As for the December 30 quake, the precise fault responsible has not yet been identified. The region’s geology, however, makes it susceptible to periodic seismic activity, even if it doesn’t sit directly atop the infamous San Andreas or Hayward faults.
This latest event capped off a particularly active week for the Susanville area. In the seven days leading up to December 30, at least three other tremors of magnitude 2.5 or higher were recorded nearby. Notably, a 4.7 magnitude quake rattled the region just two days earlier, and a 2.5 magnitude tremor was reported at 9:59 p.m. on the same night as the main event, with its epicenter about eight miles north of Susanville. The USGS received 27 felt reports for this smaller quake, which occurred at a depth of 3 miles as well.
Seismologists and emergency managers emphasize that earthquakes in the 2.5 to 5.4 magnitude range are often felt but rarely cause much damage. As Michigan Tech explains, quakes below 2.5 magnitude are seldom noticed by most people, while those in the 2.5–5.4 range may rattle nerves but typically leave infrastructure intact. Of the estimated 500,000 detectable earthquakes worldwide each year, about 100,000 are felt, and only 100 cause significant damage, according to the Department of Homeland Security.
Still, the sudden and unpredictable nature of earthquakes can trigger secondary hazards, including landslides and liquefaction, especially in areas with vulnerable soil or building types. In Lassen County, most of the population resides in structures that are considered resistant to earthquake shaking, but there are exceptions. Unreinforced brick masonry and reinforced masonry construction—common in older buildings—remain points of concern, as they can be especially vulnerable during seismic events. In this case, the USGS issued a green alert for shaking-related fatalities and economic losses, indicating a low likelihood of casualties or significant property damage.
For those who experienced the quake, the advice from experts remains consistent and clear: during an earthquake, drop, cover, and hold on. As officials repeatedly stress, “Wherever you are, drop down to your hands and knees and hold onto something sturdy.” If you’re in bed, turn face-down and cover your head with a pillow. If you’re outside, stay away from buildings and don’t rush indoors. In a car? Pull over, stop, and set your parking brake. For people using wheelchairs or walkers, the advice is to lock the wheels and remain seated until the shaking stops. The key is to protect your head and neck and to be ready for aftershocks, which can follow the main shock and sometimes cause additional hazards.
After any earthquake, hazards may linger. Officials warn of the potential for building damage, leaking gas or water lines, and downed power lines. The best course of action is to remain vigilant, inspect living spaces for hazards, and be prepared to take protective action again if aftershocks occur. As one official put it, “Expect aftershocks to follow the main shock of an earthquake. Be ready to Drop, Cover, and Hold On if you feel an aftershock.”
For those curious about the science behind these events, the USGS explains that the magnitude scale used today measures the energy released at the source of the earthquake, replacing the older Richter scale. This energy determines not only how far the quake can be felt but also its potential to cause damage. While California is no stranger to seismic activity—with Alaska, Hawaii, Oregon, Puerto Rico, and Washington also ranking high on the list of earthquake-prone areas—each event is a reminder of the need for preparedness and resilience.
In the wake of the December 30 quake, local officials and emergency managers have encouraged residents to take stock of their emergency supplies, review family communication plans, and familiarize themselves with the safest spots in their homes. And for those who felt the shaking, the USGS continues to invite reports through its online form, which helps scientists better understand the reach and impact of each event.
While the Susanville area was fortunate this time—no injuries, no major damage, just a collective sigh of relief—the quake serves as a timely reminder that, in California, the ground beneath our feet is never completely still. Staying prepared and informed remains the best defense against whatever the earth might have in store next.
