Revision History

1 revisions for "After a 7.7-Magnitude Quake Off Sanriku, Japan Confronts a Familiar Fear: Is the Next One Bigger?"

A magnitude 7.7 earthquake off Japan's Sanriku coast on April 20, 2026 triggered tsunami warnings, mass evacuations, and only the second-ever megaquake advisory for the Japan Trench — raising the estimated probability of an M8.0+ follow-on event tenfold to roughly 1%. The alert rekindles debate over prediction accuracy, infrastructure readiness, and the financial exposure of millions of uninsured households.