17:15 〜 18:30
[MIS04-P02] Similarities and disparities between radiolarian-based Sea Surface Temperature (SST) estimates with foraminifera Mg/Ca SST in monsoon influenced area
キーワード：東シナ海、放散虫、有孔虫殻のMg/Ca、東アジアンモンスーン
Radiolarian microfossils-based sea surface temperature (SST) estimates relying on statistics such as an Imbrie and Kipp type transfer function were developed in the early 1970's and showed promising results. Since, micropaleontologists tried to increase the accuracy of their reconstruction relying on more advanced statistics such as the Modern Analogue Technique or Partial Least Square method, which is an improved transfer function. The accuracy of radiolarian SST estimates may be statistically correct, however it still has an error margin around 1.2 to 1.5℃, while SST estimated using geochemical methods on foraminifera shells Mg/Ca or alkenones shows an accuracy around or less than 1.0℃. Direct comparison between both statistics and geochemical methods are not often conducted because in general, sediments rich in radiolarians have a low preservation of foraminifera and vice-versa.
The East China Sea, an area directly under the influence of the East Asian Monsoon is a marginal sea of the northwest Pacific where foraminifera preservation state is good. In the Danjo basin in the northern East China Sea, previous studies showed that at the IODP Site U1249 drilled at water depths of about 700 m, radiolarians and foraminifera are both well-preserved and thus direct comparison are possible between radiolarian and foraminiferal Mg/Ca. In this study we propose to discuss similarities and disparities between the SST reconstructed using these two methods and also to discuss the sensitivity of each proxies to the East Asian Monsoon dynamic.
The East China Sea, an area directly under the influence of the East Asian Monsoon is a marginal sea of the northwest Pacific where foraminifera preservation state is good. In the Danjo basin in the northern East China Sea, previous studies showed that at the IODP Site U1249 drilled at water depths of about 700 m, radiolarians and foraminifera are both well-preserved and thus direct comparison are possible between radiolarian and foraminiferal Mg/Ca. In this study we propose to discuss similarities and disparities between the SST reconstructed using these two methods and also to discuss the sensitivity of each proxies to the East Asian Monsoon dynamic.