Reply to comment by E. Bard et al. on “Younger Dryas sea level and meltwater pulse 1B recorded in Barbados reef crest coral Acropora palmata” by N. A. Abdul et al

• Published in: Paleoceanography 2016-12, Vol.31 (12), p.1609-1616
• Main Authors: Mortlock, Richard A., Abdul, Nicole A., Wright, James D., Fairbanks, Richard G.
• Format: Article
• Language: English
• Subjects: Acropora palmata; Acropora palmata corals; Barbados sea level; Coral reefs; Marine; Meltwater; meltwater pulse 1B; Sea level; Sea level rise; Tahiti corals; Younger Dryas sea level
• ISSN: 0883-8305; 2572-4517; 1944-9186; 2572-4525
• DOI: 10.1002/2016PA003047

Abdul et al. (2016) presented a detailed record of sea level at Barbados (13.9–9 kyr B.P.) tightly constraining the timing and amplitude during the Younger Dryas and Meltwater Pulse 1B (MWP‐1B) based on U‐Th dated reef crest coral species Acropora palmata. The Younger Dryas slow stand and the large (14 m) rapid sea level jump are not resolved in the Tahiti record. Tahiti sea level estimates are remarkably close to the Barbados sea level curve between 13.9 and 11.6 kyr but fall below the Barbados sea level curve for a few thousand years following MWP‐1B. By 9 kyr the Tahiti sea level estimates again converge with the Barbados sea level curve. Abdul et al. (2016) concluded that Tahiti reefs at the core sites did not keep up with intervals of rapidly rising sea level during MWP‐1B. We counter Bard et al. (2016) by showing (1) that there is no evidence for a hypothetical fault in Oistins Bay affecting one of the Barbados coring locations, (2) that the authors confuse the rare occurrences of A. palmata at depths >5 m with the “thickets” of A. palmata fronds representing the reef‐crest facies, and (3) that uncertainties in depth habitat proxies largely account for differences in Barbados and Tahiti sea level differences curves with A. palmata providing the most faithful proxy. Given the range in Tahiti paleodepth uncertainties at the cored sites, the most parsimonious explanation remains that Tahiti coralgal ridges did not keep up with the sea level rise of MWP‐1B. Key Points Evidence supports that Younger Dryas sea level slow stand and MWP‐1B are reliably recorded by reef‐crest coral Acropora palmata at Barbados Results indicate that Tahiti reefs reported in Bard et al. (2010) were unable to keep up with rapidly rising sea level during MWP‐1B Tahiti SL error bars are greater than reported; a full error analysis shows Tahiti overlaps with the Barbados SL curve