contribution to relative sea level rise is the earth's rebound from the ice 

 loading in the polar regions during the last (Wisconsin) ice age. This 

 rebound is causing uplift in the high latitudes on the order of 1 meter per 

 century and land subsidence at the lower latitudes on the order of 5 cm per 

 century. There have been suggestions that most of the studies of eustatic 

 rates, in excluding the high latitudes of relatively rapid uplift, have 

 yielded overestimates. A very preliminary analysis presented here based on 

 United States data tends to support this contention. 



Areas in which future studies appear warranted include: 

 1) understanding the physics of the noise in tide gage records with the 

 objective of extracting this portion of the record, 2) revisiting the 

 question of extracting recent eustatic sea level rise rates from the tide 

 gage records with an emphasis on proper recognition of the contribution 

 from glacial rebound at all latitudes, and 3) if the changes resulting from 

 2 are significant, recalibrating the models employed for predicting future 

 sea level rise based on scenarios of future changes in CO2 , other trace 

 gases and a gradual warming trend. 



2.2 LITERATURE REVIEW 



There has been a wide range of techniques and degree of sophistication 

 applied in an attempt to extract eustatic sea level rise (ESLR) from tide 

 gage records. One of the first comprehensive published studies on ESLR 

 based on tide gages was by Gutenberg (1941). A total of 69 gages was 

 analyzed encompassing the period 1807 to 1937. Gutenberg excluded tide 

 gages known to be in areas of crustal uplift, yet gages were included in 

 areas known to be sinking, some at fairly high rates. Gutenberg concluded 

 that ESLR was approximately 1 mm per year. 



Many investigations following those of Gutenberg have tended to adopt 

 his data selection procedures with similar results, i.e., rates of 1 to 1.5 

 mm/yr, see Table 2.1. Emery (1980) concluded that ESLR has been 

 accelerating with a rate up to 3 mm/yr over the past 40 years. Subsequent 

 studies by Aubrey and Emery (1983) and Barnett (1983) conducted 

 specifically to examine the change in rate concluded there was no 

 convincing evidence for such a conclusion. 



