Stable isotope record of foraminifera from the Southern Ocean

Sediment cores from the southern continental margin of Australia are near the formation region of Antarctic Intermediate Water (AAIW) and Subantarctic Mode Water and record the changes in these water masses from the last glacial maximum through the present. Carbon and oxygen isotopes were measured on the benthic foraminiferal species Planulina wuellerstrorfi for both the Recent and last glacial maximum sections of the cores and were then used to reconstruct temperature and carbon isotopic water column profiles. The glacial oxygen isotope profile indicates a vertical temperature structure for this region similar to that in today's Subantarctic Zone. Although intermediate water delta13C cannot be used as a nutrient tracer in this region because of the large influence of air-sea carbon isotopic exchange on this water mass, delta13C can be used as a water mass tracer. […]

澳大利亚南部大陆边缘的沉积岩心紧邻南极中层水（AAIW）和亚南极模态水形成区，并记录了这些水团从末次冰盛期至今的变化。对岩心中的底栖有孔虫物种Planulina wuellerstrorfi的碳和氧同位素进行了测定，这些测定分别针对近期和末次冰盛期岩心部分，并据此重建了温度和碳同位素水柱剖面。冰期氧同位素剖面表明，该区域垂直温度结构类似于现今的亚南极区。尽管由于空气-海水碳同位素交换对该水团影响巨大，因此不能将中层水δ13C作为该区域的营养示踪剂，但δ13C可以作为水团示踪剂。