Tsunami measuring system off Japan's coast malfunctions

Data from a tsunami gauge off the Pacific coast is currently unavailable, the Japan Meteorological Agency (JMA) said on July 16, raising concerns that monitoring could be delayed in the event of a major earthquake, affecting the ability to respond promptly.

The malfunctioning system is located off the coast of the Tokai region, along the Nankai Trench - an area considered to be at high risk of megathrust earthquakes. It is a key part of Japan's tsunami monitoring network. The JMA said it was unclear when the system would be restored.

The Nankai Trench stretches southwest off the Pacific coast of central Japan. The Japanese government has repeatedly urged localities in areas at high risk of major earthquakes and tsunamis to conduct regular evacuation drills.

The JMA asserted that the failure of the system installed on the seabed will not affect the issuance of initial tsunami warnings or advisories, as these warnings are mainly based on estimates of the earthquake's magnitude and epicenter.

However, the agency also admitted that there may be a delay in upgrading advisories to official warnings, depending on the observed tsunami conditions.

The system transmits data collected from the seabed via cable to a land-based monitoring station in Shizuoka Prefecture.