=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Jun-1991 Komatsushima 644/051 RLR(1976) is 8.6m below Attached BM. Attached BM (i) superceded the previous benchmark in 1994 =========================== FOLLOWING PSMSL DOCUMENTATION ADDED 23-Feb-2011 Buddy checked with Wakayama data profiles compare well. =========================== FOLLOWING PSMSL DOCUMENTATION ADDED 21-Feb-2012 A massive earthquake magnitude 9.0 occurred at 14.46 JST (05.46 UTC) on Friday 11th March 2011 with the epicentre approx. 70km east of the Oshika Peninsula of Tohoku. It was the most powerful known earthquake to hit Japan triggering a tsunami with wave up to 40.5m and travelling up to 10km inland.