The Japan Meteorological Agency lifted all tsunami warnings on Monday after a 30-centimeter tsunami was observed at Miyazaki Port [1], [2], [3].

This event demonstrates the far-reaching impact of high-magnitude seismic activity in the Pacific, as an earthquake centered far from Japan still triggered coastal alerts and measurable sea-level changes in multiple prefectures.

The tsunami was generated by a magnitude 8.2 earthquake [1] that occurred off the coast of the Philippines. The Japan Meteorological Agency monitored the resulting waves as they traveled across the ocean toward the Japanese archipelago.

At 16:46 JST on June 8, 2026, officials recorded a tsunami height of 30 centimeters [1], [2] at Miyazaki Port in Miyazaki Prefecture. Other coastal areas also experienced smaller surges. Tsunami heights of 10 centimeters [2] were observed at several locations, including Amami City Kominato, Kumano City Yuki, Minami-Ōsumi Town Ōdori, and Okinawa City Nakagusuku Bay.

While some reports indicated that the maximum predicted tsunami height for the Miyazaki area was one meter, the actual observed maximum remained 30 centimeters [2], [3]. Following these observations, the agency said the threat had subsided and cancelled all remaining warnings [1].

Local authorities in the affected prefectures had remained on alert as the waves approached. The lifting of the warnings allows port operations and coastal activities to return to normal, though officials continue to monitor seismic data from the Philippines region [1], [3].

“A 30-centimeter tsunami was observed at Miyazaki Port”

The occurrence of a measurable tsunami in Japan caused by a distant earthquake highlights the vulnerability of the Pacific Rim to trans-oceanic surges. Although the 30-centimeter wave caused minimal disruption, the discrepancy between the one-meter prediction and the actual observation underscores the challenges of real-time tsunami forecasting for high-magnitude events.