QUALITY ASSESSMENT OF SEA LEVEL DATA                
                                           by the                               
                   UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER     
                                 JOINT ARCHIVE FOR SEA LEVEL                    
                                                                                
              Station  : Norfolk Island-A          Latitude:  29 04.0S
              Country  : Australia                Longitude: 167 57.0E 
              JASL #   : 062A                 Time Meridian: 173E (GMT + 11.5)  
              GLOSS #  : 124      TOGA #: P030       NODC #: 32169701           
              Contributor  : CSIRO                                              
                             Division of Oceanography                           
                             GPO Box 1538                                       
                             Hobart, Tasmania 7001                              
              Originator   : same                                               
              Original Data: digital                                            
              Instrmnt Type: Leupold Stevens analog-to-digital recorder         
              Digitzd Intvl: 15 minutes                                         
              Present Data : Hourly, daily, and monthly values obtained by:     
                    Hourly : simple Gaussian filter                             
                    Daily  : 119-point convolution filter (Bloomfield, 1976)    
                             centered on noon applied to the hourly data        
                             with respective periods of the 95, 50, and 5%      
                             amplitude points at 124.0, 60.2, and 40.2 hours    
                    Monthly: Simple average of all daily values; calculated if  
                             7 or fewer days are missing                        
              Span of data : 13 Nov 1985 - 31 Dec 1987                          
              Gaps > 1 mon : none                                               
              Time Refernce: GMT (hours 00-23)   Space-filler Flag   :-9999     
              Units        : millimeters         Missing Data Flag   : 9999     
              Existing     : Yes                 Operational         : Yes      
              Sat. Trans.  : No                  Distribution        : 1985-1986
              Refernce Levl: All heights have been referred to the station tide
                             gauge zero which is linked to fixed benchmarks.
                             The primary Tide Gauge Benchmark is "BM 1", the
                             top of a concrete block protruding about 0.3m
                             above ground level and marked ZNI.  The tide gauge
                             zero = 5.432 m below BM 1.
              Comment      : The timing became progressively worse in 1987 due  
                             to clogging of the stilling well until it was      
                             cleaned on 25 August, 1987.  The daily and monthly 
                             values show a sharp drop on 14 July, 1987 that     
                             could possibly be a reference level shift.         
                             Correction is pending information from the         
                             originators.                                       
                                                                                
                    CI MISSING              REPLACED GAPS     QUESTIONABLE      
              YEAR (%) DATA                 OR BAD DATA       FLUCTUATIONS      
              ---- --- -------------------- --------------- --------------------
              1985  13 none                 none            none                
              1986  98 297-304              (17)295-(02)296 none                
              1987  99 365                  none            73-237