=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Jun-1991
Sumoto              643/026 RLR(1976) is 14.6m below Attached BM (i)
Where two benchmarks have the same name the later one is suffixed.
=========================== 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. 70 km east of the Oshika Peninsular . It was the most powerful earthquake to have hit Japan triggering a tsunami with waves up to 40.5m and travelling up to 10 km inland.

