Description

Title Late Deglacial (13.9 TO 8 KYR B.P.) records from the reef crest coral Acropora palmata in Barbados

Date Created 2017

Other Date 2017-01 (degree)

Extent 1 online resource (xiv, 222 p. : ill.)

Description The radioactive isotopes of Uranium and Thorium obtained from fossil reef-crest corals Acropora palmata are used to constrain and reconstruct sea level at Barbados during the late deglaciation (13.9 to 8 kyr BP). We find that sea level tracked the climate oscillations remarkably well. Sea-level rise was fast in the early Allerød (25 mm yr-1), but decreased smoothly into the Younger Dryas (7 mm yr-1) when the rate plateaued to <4 mm yr-1here termed a sea-level “slow stand”. No evidence was found indicating a jump in sea level at the beginning of the Younger Dryas as proposed by some researchers. Following the “slow-stand”, the rate of sea-level rise accelerated rapidly, producing the 14 ± 2 m sea-level jump known as MWP-1B; occurred between 11.45 and 11.1 kyr BP with peak sea-level rise reaching 40 mm yr-1. Following MWP-1B, sea-level rise rapidly decreased to 8 mm yr-1. Sea surface temperatures (SST) were reconstructed at Barbados to constrain variability in the Atlantic Warm Pool (AWP) during the deglaciation. The same A. palmata samples used in Abdul et al. (2016) were analyzed for 18O. The sea level associated with each sample allowed a direction determination of the ice volume correction to δ18O data. Applying the δ18O-SST calibration (Reynaud et al., 2007), we find a warm tropical Atlantic, > 28.5oC during the Allerød. At the start of the Younger Dryas, SSTs cooled by ~3o C possibly signaling a collapse of the large AWP. By 12.5 kyr BP, warming recommenced signaling re-establishment of the AWP at Barbados. I have laid the framework for future work on the Barbados coral collection. Reconstructing seasonality during different climate states (Bølling-Allerød vs. Younger Dryas vs. the Holocene) provides critical data for understanding how the AWP forced or responded at critical times. To quantify seasonality, high-resolution samples (~0.3 mm sample spacing using a micro-mill) on the banded coral Montastrea annularis were analyzed. Preliminary results show that extension rates for M. annularis were low (< 5 mm yr-1) which limits temporal resolution but more importantly may introduce kinetic effects into the incorporation of stable isotopes into the coral skeleton.

Note Ph.D.

Note Includes bibliographical references

Note by Nicole Allyson Abdul

Genre theses

Persistent URL https://doi.org/doi:10.7282/T3FJ2K64

Language eng

Collection Graduate School - New Brunswick Electronic Theses and Dissertations

Organization Name Rutgers, The State University of New Jersey