Journal of Tropical Oceanography ›› 2014, Vol. 33 ›› Issue (2): 94-100.doi: 10.11978/j.issn.1009-5470.2014.02.013cstr: 32234.14.j.issn.1009-5470.2014.02.013

• Marine Geology • Previous Articles     Next Articles

Salinity effect on Holocene Mg/Ca-temperature estimation from the Indo-Pacific warm-pool sediment samples

WANG Wen-jie, XU Jian   

  1. Institute of Cenozoic Geology and Environment, State Key Laboratory of Continental Dynamics and Department of Geology, Northwest University, Xi’an 710069, China
  • Received:2013-05-07 Revised:2013-08-23 Online:2014-04-02 Published:2014-04-02
  • Contact: 高等学校博士学科点专项科研基金(20096101120025); 国家自然科学基金项目(40906032、41176044); 大陆动力学国家重点实验室自主研究课题(BJ11052)

Abstract: 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.

Key words: sea surface temperature, Mg/Ca-thermometer, Indo-Pacific warm pool, Holocene

CLC Number: 

  • P736.4