Influence of tidal-range change and sediment compaction on Holocene relative sea-level change in New Jersey, USA

We investigated the effect of tidal-range change and sediment compaction on reconstructions of Holocene relative sea level (RSL) in New Jersey, USA. We updated a published sea-level database to generate 50 sea-level index points and ten limiting dates that define continuously rising RSL in New Jersey during the Holocene. There is scatter among the index points, particularly those older than 7 ka. A numerical model estimated that paleotidal range was relatively constant during the mid and late Holocene, but rapidly increased between 9 and 8 ka, leading to an underestimation of RSL by ∼0.5m. We adjusted the sea-level index points using the paleotidal model prior to assessing the influence of compaction on organic samples with clastic deposits above and below (an intercalated sea-level index point). We found a significant relationship (p=0.01) with the thickness of the overburden (r=0.85). We altered the altitude of intercalated index points using this simple stratigraphic relationship, which reduced vertical scatter in sea-level reconstructions. We conclude that RSL rose at an average rate of 4mm a^-1 from 10 ka to 6 ka, 2mm a^-1 from 6 ka to 2 ka, and 1.3mm a^-1 from 2 ka to AD 1900.