An earthquake struck Japan&rsquo;s Shimane prefecture on Tuesday, initially reported at a magnitude of 6.3 before being revised downward, according to the Japan Meteorological Agency (JMA). The epicentre was located in the eastern part of Shimane, and authorities confirmed that no tsunami warning was issued.
The JMA later downgraded the earthquake&rsquo;s magnitude to 4.5, while real-time data from the United States Geological Survey placed it higher, at 5.8. Despite the differing assessments, the quake was felt strongly in parts of the prefecture and registered an upper-5 intensity on Japan&rsquo;s seven-point seismic scale, local broadcaster NHK reported.
Japan remains deeply sensitive to seismic activity following the devastating 9.0 magnitude undersea earthquake in 2011, which triggered a massive tsunami and left around 18,500 people dead or missing.
Concerns over a potential large-scale disaster persist. In August 2024, the Japan Meteorological Agency issued its first-ever special advisory warning of a possible megaquake along the Nankai Trough, a roughly 800-kilometre-long undersea trench where the Philippine Sea tectonic plate is slowly sliding beneath the continental plate supporting Japan.
Government estimates suggest that a major earthquake in this zone, followed by a tsunami, could result in up to 298,000 deaths and economic losses nearing $2 trillion.
Japan is one of the world&rsquo;s most earthquake-prone countries, located along the Pacific Ring of Fire where four major tectonic plates meet. The country experiences around 1,500 tremors annually, most of them minor, though the potential impact depends on depth, location, and timing.

Magnitude revised as quake shakes prefecture, authorities monitor impact

Japan Earthquake Hits Shimane, No Tsunami Alert

Magnitude revised as quake shakes prefecture, authorities monitor impact

January 6, 2026 | 11:19 IST