Coral Reefs

, Volume 24, Issue 1, pp 23-29

First online:

Influence of seawater Sr content on coral Sr/Ca and Sr thermometry

  • Y. SunAffiliated withDepartment of Earth Sciences, The University of Hong Kong
  • , M. SunAffiliated withDepartment of Earth Sciences, The University of Hong Kong Email author 
  • , T. LeeAffiliated withInstitute of Earth Sciences, Academia Sinica
  • , B. NieAffiliated withSouth China Sea Institute of Oceanography, Chinese Academy of Sciences

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


The Ca content of a Porites coral from Xisha, South China Sea is quite uniform along its 18-year growth axis. A comparison with previously published data shows that the Ca content of corals from different sites varies by only 0.4%. This is much smaller than the variation of Ca in seawater (2.2%), indicating that Ca variations in seawater do not significantly affect the Ca compositions of coral skeletons. The variation in skeletal Ca contents results in only ±0.6°C of uncertainty in SST calculations, which is much smaller than the large disparities observed for previously established coral Sr/Ca thermometers. In contrast, Sr in tropical seawater varies spatially by as much as 2.4%, corresponding to ~4°C offset for coral Sr/Ca calibrations. The effect of seawater Sr variations on coral Sr/Ca thermometers is evaluated and we demonstrate that the content of seawater Sr is the major factor responsible for disparities in these coral Sr/Ca thermometers. The disparities can be significantly reduced when seawater Sr contents are included in the Sr/Ca thermometers.


Coral Sr/Ca thermometry Sea-surface temperature Coral Ca content Seawater Sr concentration