=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Jun-1991 Mera 642/061 RLR(1976) is 11.2m below Attached BM =========================== FOLLOWING PSMSL DOCUMENTATION ADDED 12-Jul-1993 Several apparent datum problems in the 1950s and 1960s =========================== FOLLOWING PSMSL DOCUMENTATION ADDED 22-Feb-2011 By buddy checking the data for Mera against that for Aburatsubo and adding the residuals there does seem to be datum problems during the late 40's through to the mid 60's. =========================== FOLLOWING PSMSL DOCUMENTATION ADDED 21-Feb-2012 A massive earthquake of magnitude 9.0 occurred at 14:46 JST (05:46 UTC) on Friday 11th March 2011 with the epicenter approx. 70km east of the Oshika Peninsula of Tohoku. It was the most powerful known earthquake to hit Japan generating a tsunami with waves up to 40.5m travelling up to 10km inland. =========================== FOLLOWING PSMSL DOCUMENTATION ADDED 13-Mar-2014 The GPS benchmark information has been downloaded from the SONEL website. GPS benchmark P206 is 16.204m above RLR.