Organic geochemical parameters (biomarker) in sedimentary sequences and sediment traps

For the reconstruction of sea-ice variability, a biomarker approach which is based on (1) the determination of sea-ice diatom-specific highly-branched isoprenoid (IP25) and (2) the coupling of phytoplankton biomarkers and IP25 has been used. For the first time, such a data set was obtained from an array of two sediment traps deployed at the southern Lomonosov Ridge in the central Arctic Ocean at water depth of 150 m and 1550 m and recording the seasonal variability of sea ice cover in 1995/1996. These data indicate a predominantly permanent sea ice cover at the trap location between November 1995 and June 1996, an ice-edge situation with increased phytoplankton productivity and sea-ice algae input in July/August 1996, and the start of new-ice formation in late September. The record of modern sea-ice variability is then used to better interpret data from sediment core PS2458-4 recovered at the Laptev Sea continental slope close to the interception with Lomonosov Ridge and recording the post-glacial to Holocene change in sea-ice cover. […]为重建海冰变化序列，本研究采用了基于两项核心内容的生物标志物法：（1）海冰硅藻特异性高分支类异戊二烯烃（IP25）的测定；（2）浮游植物生物标志物与IP25的耦合分析。本数据集首次通过部署于北冰洋中部罗蒙诺索夫海岭（Lomonosov Ridge）南部、水深分别为150 m与1550 m的两套沉积捕集器（sediment trap）阵列获取，完整记录了1995/1996年的海冰覆盖季节变化特征。监测数据显示，1995年11月至1996年6月期间，捕集器部署海域以常年稳定海冰覆盖为主；1996年7—8月进入冰缘环境，浮游植物生产力与海冰藻类输入量均显著升高；同年9月下旬则迎来新冰形成阶段。随后，这套现代海冰变化序列被用于更精准地解读拉普捷夫海大陆坡（邻近罗蒙诺索夫海岭交会区）获取的沉积岩芯（sediment core）PS2458-4的相关数据——该岩芯完整记录了冰期后至全新世的海冰覆盖演化过程。[……]