Japan Trench re-locking and megaquake warning

What happened before and after this story. Background events not previously covered were summarised by AI.

1. 11 Mar 2011Background

   M9.0 Tohoku earthquake and tsunami strike Japan's northeast coast

   On 11 March 2011 a magnitude 9.0 quake on the Japan Trench sent a huge tsunami onto Japan's northeast coast and triggered the Fukushima nuclear disaster.

2. 

   10 Nov

   Japan Trench is locking up again, scientists warn, as in the run-up to 2011

   Seafloor data suggest the fault behind the 2011 Tohoku quake has locked again, and researchers say the next big one could come sooner than long-term averages.