Foraminiferal Mg/Ca-thermometer is one of the key methods in reconstructing past ocean temperatures. Increasing evidence, however, revealed that precision of Mg/Ca-thermometer is influenced by various factors in addition to seawater temperature. Of these factors, salinity is in particular highlighted. This study measured and collected an amount of more than one thousand Holocene (since about 11 ka B.P.) foraminiferal Mg/Ca ratios from sediment cores recovered from the Indo-Pacific warm pool. These Mg/Ca ratios were converted into temperatures using two conventional equations, with and without salinity involved. Estimated temperatures were then compared to reveal salinity effects on Mg/Ca-thermometer used for samples from the Indo-Pacific warm-pool region. It is shown that values resulted from the two equations are very similar, with a difference of 0.07℃ on average in the case that the estimated temperature is lower than 28℃. In contrast, difference is up to 1℃ when the estimated temperature is higher than 28℃. Moreover, it is also revealed that less saline water and larger seawater oxygen isotope were estimated using the equation involving salinity. These findings imply that salinity likely had little influence on foraminiferal Mg/Ca in this region.
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