Holocene environmental conditions in the coastal ocean off East Antarctica - evidence from the paleo-diet of snow petrels

南极洲东部沿海海洋的全新世环境条件——来自雪海燕古饮食的证据

• 批准号: 522373452
• 负责人: Dr. Sonja Berg
• 金额: --
• 依托单位: Institut für Geologie und Mineralogie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/522373452?language=en
• 关键词: Holocene; environmental; conditions; coastal; ocean

Reconstructions of past environmental conditions in the coastal ocean off East Antarctica are crucial to better understand processes of ocean - ice interaction. For the proposed project, stomach oil deposits of snow petrels (Pagodroma nivea) (Antarctic mumiyo) shall be used as a paleoenvironmental archive of Holocene sea-ice conditions in the coastal zone of the Southern Ocean. A multiproxy approach, combining inorganic, lipid (fatty acids) and isotope (δ13C and δ15N) analyses will be applied to infer past changes in snow petrel diet, which can be linked to environmental conditions in the foraging range of the birds, such as sea ice variability, polynya activity and primary production. The study area comprises a large sector of the East Antarctic coastline, ranging from Wilkes Land (Windmill Islands) to Mac Robertson Land (Framnes Mountains) and is not well-covered by sea-ice records from the coastal zone. At the same time, some outlet glacier systems along this part of the coastline are sensitive to ocean warming, highlighting the need for a better understanding of ocean - ice interaction under changing climatic conditions in these regions. The research questions that will be addressed with this project are, if changes in Holocene sea ice coverage in the coastal zone i) occurred consistently across the East Antarctic margin, ii) were associated with shifts in the position of oceanic fronts, such as the southern boundary of the Antarctic Circumpolar Current and iii) are correlated with the advance/retreat of the ice sheet margin and/or its outlet glacier systems. To extent the existing sample set, sampling of mumiyo deposits in un-glaciated coastal sites (Windmill Islands, Bunger Hills, Gaussberg and Vestfold Hills) is part of the proposed project. Field work will be conducted within the scope of the RV Polarstern expeditions PS140 (EASI 2) and PS141 (EASI 3) that are scheduled back-to-back for the austral summer season 2023/24.

重建东南极洲沿海海洋过去的环境条件对于更好地了解海洋与冰相互作用的过程至关重要。对于拟议的项目，雪海燕（Pagodroma nivea）（南极mumiyo）的胃油沉积物将被用作南大洋沿海地区全新世海冰状况的古环境档案。将采用结合无机、脂质（脂肪酸）和同位素（δ13C 和 δ15N）分析的多代理方法来推断雪海燕饮食的过去变化，这可以与鸟类觅食范围内的环境条件（例如海冰变化、冰间湖活动和初级生产）联系起来。研究区域包括南极东部海岸线的大部分区域，从威尔克斯地（风车群岛）到麦克罗伯逊地（弗拉姆内斯山脉），并且沿海地区的海冰记录并未充分覆盖。与此同时，沿着这部分海岸线的一些出口冰川系统对海洋变暖很敏感，这突出表明需要更好地了解这些地区不断变化的气候条件下海洋与冰的相互作用。该项目将解决的研究问题是，沿海地区全新世海冰覆盖范围的变化是否i）在南极东部边缘持续发生，ii）与海洋锋位置的变化有关，例如南极绕极流的南部边界，以及iii）与冰盖边缘和/或其出口冰川系统的前进/后退相关。为了扩大现有样本集，拟议项目的一部分是在非冰川沿海地点（风车群岛、邦格山、高斯伯格和韦斯特福尔德山）对木美约沉积物进行采样。实地工作将在 RV Polarstern 探险 PS140 (EASI 2) 和 PS141 (EASI 3) 范围内进行，这两个探险计划在 2023/24 年南方夏季连续进行。