Reef growth and the Late Holocene climatic change recorded in the Raised Coral Reef in Kikai-jima Islands, Ryukyu, Japan.

1996年和1997年，对日本西南部琉球岛Kikai-jima岛北部海岸七岛岛周围的全新世隆起珊瑚礁和现代珊瑚礁进行了实地调查。用本中心配备的手动取样器获得了6个岩心样品(T-1~T-6)，长度为2.44~3.99分钟，直径为5厘米。在阶地II-IV上，横纹型珊瑚组合中以扁平和包壳的风信子、风信子、双子藻和芒果珊瑚为主。物种组合表明，所有岩心都沉积在0~10min深度的浅海环境中。活着的Porites spp.的骨骼，Tridacna spp.在岛礁岸边的珊瑚礁斜坡上，每隔5米采集0~30min深度的海水样品，在实验室拍摄活珊瑚和全新世珊瑚板的软X射线照片，并研究年生长带以确定样品的年代。活体标本(KS01-09)取自9min深度。化石样品的U系列年龄(1805)在Ota等人(1998)之后为9.2 ka。用质谱仪测定了珊瑚骨架的碳、氧稳定同位素比值。利用日本海洋与大气研究中心的IGOSS海温资料和1ﾟ网格盐度资料，分别重建了基开岛附近的现今海温和月平均盐度，并根据氧同位素异常模式估算了基开吉马岛附近的古盐度和现今盐度。预测目前海温平均值为21.9ﾟC，比实测值低2.6ﾟC。全新世早期海温平均值也估计为22.0ﾟC，与传递函数计算结果不一致。

Field surveys on the Holocene Raised Coral Reef and present coral reefs around Shido-oke in the northern coast of Kikai-jima Island, Ryukyus, southwest Japan were carried out in 1996 and 1997. Six core samples (T-1-T-6) ranging from 2.44 to 3.99 min length and 5 cm in diameter were obtained by using hand corer which was equipped by this Grant. on the Terraces II to IV.Tabular and encrusting Acropora, such as A.hyacinthus, A.digitifera, A.gemmifera, and A.monticulosa predominate in the hermatypic coral assemblages. Species combination indicates that the all cores were deposited in the shallow marine environments from 0 to 10 min depth. Skeletons of the living Porites spp., Tridacna spp. and sea water samples were collected from every 5 m from 0 to 30 min depth on the reef slope off Shido-oke.SoftX-ray photos of the living and Holocene coral slabs were taken in the laboratory and the annual growth bands were studied to date the samples. The living (KS01-09) sample was taken from 9 min depth. Useries age of the fossil sample (1805) is 9.2 ka after Ota et al.(1998). Carbon and oxygen stable isotope ratios of the coral skeleton were measured by the mass spectrometry. Present sea surface temperature (SST) and monthly mean salinity around Kikai-jima Island are reconstructed from IGOSS SST data and 1ﾟ mesh salinity data of JODC,respectively.Paleo- and present SSTs around Kikai-jima were estimated according to the oxygen isotope anomaly model including the vital effects and the ice sheet size. It predicts that-the present mean SST is 21.9ﾟC,2.6ﾟC lower than the actually measured data. Early Holocene mean SST was also estimated to be 22.0ﾟC,which is discordant with the results calculated on the transfer function..