Multiple Earthquakes Shake California, Raising Concerns of Major Seismic Activity

HAYWARD, Calif. (AP) — A series of tremors rattled California on Thursday, with at least four earthquakes striking near Hayward, according to the U.S. Geological Survey (USGS). The quakes, which registered preliminary magnitudes between 2.7 and 3.7, were felt across a wide area, prompting local residents to report the shaking as far away as Concord and Fremont.

The first earthquake, measured at 2.7 magnitude, hit at 5:08 a.m. A more sizable quake followed shortly before noon, registering 3.3, along with another of 3.2 magnitude just two minutes later. The most significant tremor, a 3.7-magnitude quake, occurred shortly before 2 p.m. No injuries or damages have been reported thus far.

In addition to those in Hayward, another significant earthquake, measured at 4.4 magnitude, struck between Coalinga and Avenal in Fresno County at about 4:17 p.m. Residents near the quake’s epicenter felt the shaking, and the USGS activated California’s Shake Alert system as a precaution.

The day’s seismic activity did not stop there. The USGS reported additional quakes later in the day near Petrolia, California, further underscoring the region’s ongoing geological unrest. The first of these later quakes struck at 2:40 p.m. near Petrolia, measuring 2.9, followed by a 3.4 magnitude quake in Hayward at 2:52 p.m., approximately two minutes after a 3.2 magnitude quake.

Scientists are particularly attentive to these developments as they occur near the Hayward fault line, notorious for its seismic potential. The last major earthquake along this fault was recorded on October 21, 1868, with a magnitude of 6.8, resulting in casualties and extensive damage.

According to researchers at the University of California, Berkeley, there is a significant chance of a large earthquake occurring in the next few decades. “Since it has been more than 144 years since the last major earthquake, the clock is ticking,” said a university researcher. “It is very likely that the Hayward fault will rupture and produce a significant earthquake within the next 30 years.”

The tremors observed on Thursday are consistent with previous activity along the Pacific Plate, which is known for large tectonic movements. A 2024 study suggested deep underwater faults might be causing these large plates to pull apart, posing additional risks for future seismic events.

The San Andreas fault, located not far from Hayward, also presents a serious risk, with experts warning that California awaits another major earthquake, potentially causing catastrophic damage to the state’s urban areas. Estimates suggest a magnitude 8 quake could lead to approximately 1,800 deaths and $200 billion in economic losses.

As California residents brace themselves for the potential of more significant seismic events, experts encourage those living in earthquake-prone areas to prepare earthquake kits and have emergency plans in place.