|Title||Reply to Grinsted et al.: Estimating land subsidence in North Carolina|
|Publication Type||Journal Article|
|Year of Publication||2011|
|Authors||Kemp AC, Horton BP, Donnelly JP, Mann ME, Vermeer M, Rahmstorf S|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
Reconstructions and observations of relative sea level (RSL) must be corrected for vertical land movements from glacial isostatic adjustment (GIA) to facilitate comparisons among regions and identify deviations from background rates. Late Holocene (past 2 ka) GIA rates are estimated from geological data and permanent global positioning system (GPS) stations or predicted from GIA models. We used a linear trend fitted to the regional, compaction-free, RSL reconstructions compiled by Engelhart et al. (1) for the past 2 ka (excluding data since AD 1900) as a GIA estimate. Similarly, GIA models also attribute all RSL changes during the past 2 ka to linear GIA and have zero eustatic (e.g., meltwater) contribution.