=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 11-Jun-1991
Mantyluoto          060/101 RLR(1964) is 9.7m below BM52307
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 24-Sep-2002
A description of the sea level network in Finland can be found in 'Operational Oceanography: Implementation at the European and Regional scales.  2002 (pp.129-137)'.
1910-1924 Values based on 1 reading per day. Prior to 1970 gauge at 61 36 N, 21 29 E
1925-1970 Values based on 6 readuings a day
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 03-Jan-2012
Prior to the gauge being moved the Primary benchmark 1925-1969 was 52307 4.407m above gauge datum. When the gauge was moved benchmark 1970-1988 was N7101 4.774m relative to the datum. This is no longer used and was replaced by 89110 3.970m relative to gauge datum in 1989.
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 31-Jan-2017
Following the 2016 levelling exercise some adjustments have been made to the benchmark reference heights - at Mantyluoto this was +2mm for BM 89110. The adjustments are a result of more accurate measuring and calculations using the N2000 height system. The RLR diagram has been re-drawn because of this.
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 20-Dec-2017
Data values for November and December 2014 have been revised by the Finnish Meteorological Institute.
=========================== FOLLOWING PSMSL DOCUMENTATION ADDED 27-Nov-2019
From 2018 onwards the averages of the Finnish sea level data will be based on 1 min observations. Values are calculated in Finnish normal time (EET).
The data are relative to the reference surface of the Finnish sea level observations and thus the datum is the tide gauge zero.

