A 5.4‑magnitude earthquake struck the northeast coast of Honshu, Japan, on Wednesday, October 29, 2026, according to the German Research Centre for Geosciences (GFZ). The event occurred at 15:07 GMT and was first cataloged by GFZ as having a depth of 49.4 km, with coordinates 35.67° N, 140.59° E.
The Japan Meteorological Agency (JMA) issued an alert at 12:07 a.m. local time, reporting a preliminary magnitude of 5.4 at an approximate depth of 50 km in Chiba Prefecture, near Tokyo. The alert stated that the quake was of lower‑5 intensity on the Japanese seismic intensity scale and that no tsunami warning had been issued.
Kyodo News later indicated that the preliminary magnitude was later refined to 5.5, noting that the event generated a lower‑5 reading at Yokoshibahikari and weaker shaking in other parts of the prefecture. The JMA’s initial estimate was 5.4, highlighting a small difference in the early reporting.
According to Kyodo, the shaking was felt throughout Chiba and in neighboring prefectures such as Tochigi, Ibaraki, and Saitama. The Viggies of the Japanese seismic intensity scale indicated only mild damage potential, consistent with the warning that no tsunami posed a threat.
The event was included in Kyodo’s daily digest for October 29, 2026, where it was characterized as a 5.5‑magnitude quake in Chiba Prefecture with no tsunami risk, underscoring the rapid updates between local and international seismic monitoring agencies.
Both GFZ and the JMA confirmed that the depth of almost 50 km places the earthquake within the open ocean seafloor, which is why no tsunami was expected. The coordinated reporting from the German and Japanese centers illustrates the global nature of seismic monitoring, blending local intensity assessment with international seismological analysis.
