Magnitude 4.0 Earthquake Hits Chiba, Japan, September 9, 2025

Kisarazu, Japan – A magnitude 4.0 earthquake struck near Kisarazu in Chiba Prefecture on Tuesday, September 9, 2025, at 8:53 a.m. local time, according to the European-Mediterranean Seismological Centre (EMSC). The quake occurred at a depth of 70 kilometers and was reportedly felt in several neighboring towns.

The National Research Institute for Earth Science and Disaster Resilience (NIED) reported the quake’s magnitude as 4.3, while citizen reporting from the RaspberryShake network confirmed it at 4.0. The slight discrepancy in magnitude highlights the ongoing research and monitoring of seismic activity in the region.

The quake’s epicenter was approximately 2 kilometers from Sodegaura (population 64,900), 6 kilometers from Kisarazu (population 136,200), and 15 kilometers from Ichihara (population 283,500). Residents in these areas reported very weak shaking, though no significant damage has been reported. Major cities like Tokyo (population 8,336,600) and Yokohama (population 3,761,600) experienced minor tremors, with residents indicating they felt light shaking.

Local authorities were quick to urge residents to be vigilant as aftershocks may occur. The Japan Meteorological Agency will continue to monitor the situation and provide updates as necessary.

People who felt the earthquake are encouraged to report their experiences to aid in assessing the earthquake’s impact. The data collected will assist researchers in understanding Earth’s seismic activity more thoroughly.

Seismologists are analyzing the data and may revise the quake’s parameters as more information becomes available.