Japan experiences 6.1‑magnitude quake off Iwate coast, no tsunami warning

A magnitude 6.1 earthquake struck offshore Iwate Prefecture in northeastern Japan at 5:21 a.m. local time on June 28, with a depth of about 40 km. The Japan Meteorological Agency reported no tsunami risk and recorded a maximum seismic intensity of lower 5 on the national scale. Prime Minister Sanae Takaichi posted on X that the government is continuing its response through the crisis‑management office set up after a stronger, magnitude 7.2 quake on June 25, and urged residents to stay vigilant for aftershocks, rockfalls and landslides.

The same week saw several other tremors: a 5.7‑magnitude quake on Honshu, a 5.6‑magnitude event near Mount Fuji, and earlier offshore shocks of magnitude 6.9 and 7.2. No casualties or significant damage have been reported.

Separately, a new geophysical study highlighted that the 2011‑March‑11 Tōhoku megathrust earthquake generated deep‑travelling seismic waves that temporarily displaced the entire Japanese archipelago eastward by 5‑6 mm. Researchers say the phenomenon reveals a previously unrecognized source of seismic risk that could aid future forecasting.