QUALITY ASSESSMENT OF SEA LEVEL DATA                
                                           by the                               
                   UH SEA LEVEL CENTER/NATIONAL OCEANOGRAPHIC DATA CENTER     
                                 JOINT ARCHIVE FOR SEA LEVEL                    
                                                                                
              Station  : Easter-A                  Latitude:  27 09.0S          
              Country  : Chile                    Longitude: 109 26.9W          
              JASL #   : 022A                 Time Meridian: 090W (GMT - 6 hr)  
              GLOSS #  : 137  Originator #:0305      NODC #: 52107901           
              Contributor  : Instituto Hidrografico de la Armada (IHA)          
                             Casilla 324                                        
                             Valparaiso, Chile                                  
              Originator   : same                                               
              Original Data: analog                                             
              Instrmnt Type: standard mechanical gauge                          
              Digitzd Intvl: one hour                                           
              Present Data : Hourly, daily, and monthly values obtained by:     
                    Hourly : The original digitizing interval was hourly        
                    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 : 16 Jan 1957 - 31 Dec 1958                          
              Gaps > 1 mon : none                                               
              Time Refernce: GMT (hours 00-23)   Space-filler Flag   :-9999     
              Units        : millimeters         Missing Data Flag   : 9999     
              Existing     : No                  Operational         : No       
              Sat. Trans.  : No                  Distribution        : 1957-1958
              Refernce Levl: The data have apparently been corrected with       
                             comparative readings from the station tide staff   
                             which is linked to fixed bench marks.  However,    
                             these bench marks are not linked to the            
                             bench marks used by other data sets for Easter     
                             Island; thus, this data record is independent.     
              Comment      : The daily and monthly means reveal no apparent     
                             reference level shifts or trends.                  
                                                                                
                    CI MISSING              REPLACED GAPS     QUESTIONABLE      
              YEAR (%) DATA                 OR BAD DATA       FLUCTUATIONS      
              ---- --- -------------------- --------------- --------------------
              1957  96 none                 none            105,183-184,307     
              1958  95 121-127,192-203      (13)314-(20)314 none