TY - JOUR
T1 - Improving analytical method of Sr/Ca ratios in coral skeletons for paleo-SST reconstructions using ICP-OES
AU - Watanabe, Takaaki K.
AU - Watanabe, Tsuyoshi
AU - Ohmori, Kazuto
AU - Yamazaki, Atsuko
N1 - Funding Information:
We thank all CREES members for helping to manage ICP‐OES. The logger‐based SST data were provided from KIKAI Institute for coral reef sciences. We acknowledge for preparing coral slabs to Hidehiko Nomura, and Kousuke Nakamura. This study was supported by JSPS KAKENHI Grant Number JP25257207 and 17H04708.
Publisher Copyright:
© 2020 Association for the Sciences of Limnology and Oceanography
PY - 2020/6/1
Y1 - 2020/6/1
N2 - Strontium/calcium ratios (Sr/Ca) in reef coral skeletons have been used for sea surface temperature (SST) proxy. Because skeletons of reef corals are accumulated throughout more than 100 years, SST records from coral skeletons were important archives to reveal climate mechanisms. Here, we improved the coral Sr/Ca analytical method using an inductively coupled plasma optical emission spectrometer which method has advantages in terms of initial/running cost and analysis time. We checked variations of Sr and Ca sensitivities as increases of Ca concentrations using various wavelengths of Sr and Ca. Our results suggested that sensitivities of Sr/Ca in a range of coral skeletons were modulated by selections of wavelengths and sensitivity changes of Sr and Ca. A combination of Sr(421.5 nm) and Ca(373.6 nm) is stable for the Sr/Ca analysis at a low Ca concentration. A SD of Sr/Ca(421.5/373.6 nm) was 0.006 mmol mol−1 (1σ, n = 40) based on the replicate measurement of the reference material (JCp-1) using our new method. By applying a Porites colony from Kikai island, Japan, a precision of reconstructed SST was over ± 0.3°C at weekly resolution.
AB - Strontium/calcium ratios (Sr/Ca) in reef coral skeletons have been used for sea surface temperature (SST) proxy. Because skeletons of reef corals are accumulated throughout more than 100 years, SST records from coral skeletons were important archives to reveal climate mechanisms. Here, we improved the coral Sr/Ca analytical method using an inductively coupled plasma optical emission spectrometer which method has advantages in terms of initial/running cost and analysis time. We checked variations of Sr and Ca sensitivities as increases of Ca concentrations using various wavelengths of Sr and Ca. Our results suggested that sensitivities of Sr/Ca in a range of coral skeletons were modulated by selections of wavelengths and sensitivity changes of Sr and Ca. A combination of Sr(421.5 nm) and Ca(373.6 nm) is stable for the Sr/Ca analysis at a low Ca concentration. A SD of Sr/Ca(421.5/373.6 nm) was 0.006 mmol mol−1 (1σ, n = 40) based on the replicate measurement of the reference material (JCp-1) using our new method. By applying a Porites colony from Kikai island, Japan, a precision of reconstructed SST was over ± 0.3°C at weekly resolution.
UR - http://www.scopus.com/inward/record.url?scp=85083518498&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85083518498&partnerID=8YFLogxK
U2 - 10.1002/lom3.10357
DO - 10.1002/lom3.10357
M3 - Article
AN - SCOPUS:85083518498
SN - 1541-5856
VL - 18
SP - 297
EP - 310
JO - Limnology and Oceanography: Methods
JF - Limnology and Oceanography: Methods
IS - 6
ER -
