Just out | Diploastrea heliopora Sr/Ca and δ18O records from northeast Luzon, Philippines: an assessment of inter-species coral proxy calibrations and climate controls of sea surface temperature and salinity @ Paleoceanography


Just out @ Paleoceanography


Diploastrea heliopora Sr/Ca and δ18O records from northeast Luzon, Philippines: an assessment of inter-species coral proxy calibrations and climate controls of sea surface temperature and salinity


Author(s)

R. D. Ramos, N. F. Goodkin, F. P. Siringan, K. Hughen


Abstract:

The Indo-Pacific coral Diploastrea heliopora reveals regional multi-decadal to centennial scale climate variability using coral carbonate δ18O (δ18Oc) as a combined proxy for sea surface temperature (SST) and sea surface salinity (SSS). However, to assess the coral’s full potential in resolving climatic events, an independent SST proxy would be more advantageous. We examined both Sr/Ca and δ18O of Diploastrea against an adjacent Porites lobata core collected from northeast Luzon, Philippines. Winter Sr/Ca data from Diploastrea show a significant correlation to SST (r = -0.41, p < 0 .05, RMSR = 0.81 °C) and provide a proxy with similar sensitivity as Porites (r = -0.57, p < 0.05, RMSR = 0.62 °C). An inter-species SST record is shown to be robust and used for a reconstruction of the Pacific Decadal Oscillation (PDO) during boreal winter (r = -0.70, p = 0.02). While we were unable to generate a robust Diploastrea δ18O-SSS calibration at inter-annual timescale, the freshening trend towards the present, commonly observed in the region, is qualitatively captured in Diploastrea δ18O. Comparison with Porites δ18O and instrumental SSS records shows that the magnitude of freshening is consistent between coral species. Wet and dry season Porites δ18O provide support for the relative influence of El Niño Southern Oscillation (ENSO) events and local precipitation to SSS variability at our site. The multi-proxy, multi-species approach of this study further strengthens the evidence for Diploastrea as an alternate climate archive in the Indo-Pacific region, and seals its potential in helping resolve less understood global-scale climate phenomena.

YOU MAY ALSO LIKE  Just out | Hierarchical complexity and the size limits of life @ Proceedings of the Royal Society B

READ IT HERE:

http://onlinelibrary.wiley.com/doi/10.1002/2017PA003098/abstract


(image credit: click here for source)

Lurdes Fonseca

Assistant Professor and Researcher at University of Lisbon
Sociologist (PhD), Paleontologist (Researcher in Micropaleontology), Majors in Sociology and Biology, Minor in Geology. Main interests in Paleontology: Microfossils, Molecular fossils, Paleobiology and Paleoecology. (read more about me)