An automated Japan Meteorological Agency alert confirmed a 5.4‑magnitude earthquake near Chiba Prefecture at 12:07 a.m. on Oct. 29, 2026. The preliminary report listed a depth of 50 km and a seismic intensity of lower‑5 on the 1‑7 scale. No tsunami warning followed the alert.
The epicenter was pinpointed at N 35.7, E 140.7, placing the fault zone roughly 70 km east of central Tokyo. The shallow depth contributed to the intensity reading that was likely felt by residents in northern Chiba and parts of western Tokyo.
Kyoto-Based emergency services immediately checked and confirmed that the local earthquake monitoring network registered the strike. Alerts were sent via the national emergency broadcast system, and civilian smartphones received automated messages through pre‑installed notification apps.
Officials emphasized that while the quake was moderate, its proximity to densely populated areas warranted vigilance. Local authorities urged residents to secure loose items and stay away from high places until aftershocks subsided.
The automated alert system is part of a decade‑long effort to deliver near‑real‑time information on seismic activity. Earlier this year, similar alerts prompted a rapid response to a 4.9‑magnitude event in Shizuoka.
