Modelling holocene relative sea-level observations from the Caribbean and South America.

Abstract

Holocene data from the Caribbean and the Atlantic coast of South America have been critically assessed and a subset of the best quality data are presented. These data cover a large north–south geographic extent and display a distinct spatial variation. We make the first comparisons of this data set to predictions based on a realistic model of glaciation-induced sea-level change with the main aims of understanding the cause of the observed spatial trend and estimating a eustatic signal for the Holocene. The spatial variation is dominated by the influence of the ice and ocean mass redistribution on sea-level change, with the ice-induced effect dominating the observed north–south trend. A best-fitting model is applied to estimate a Holocene eustatic signal from the observations. We find that the model-corrected data are consistent with a relatively rapid rise of 7–8 mm/yr in the early Holocene with a marked reduction in this rate around 7 cal. kyr BP. From this time until present, the model-corrected data suggest that the volume of mass transfer between ice sheets and oceans was no more than (eustatic sea-level equivalent).