文章基本信息

标题：Modelling the Antarctic Ice Sheet across the mid-Pleistocene transition – implications for Oldest Ice
本地全文：下载
作者：Johannes Sutter ; Hubertus Fischer ; Klaus Grosfeld 等
期刊名称：The Cryosphere
印刷版ISSN：1994-0416
电子版ISSN：1994-0424
出版年度：2019
卷号：13
期号：7
页码：2023-2041
DOI：10.5194/tc-13-2023-2019
出版社：Copernicus Publications
摘要：The international endeavour to retrieve a continuous ice core, which spans the middle Pleistocene climate transition ca. 1.2–0.9 Myr ago, encompasses a multitude of field and model-based pre-site surveys. We expand on the current efforts to locate a suitable drilling site for the oldest Antarctic ice core by means of 3-D continental ice-sheet modelling. To this end, we present an ensemble of ice-sheet simulations spanning the last 2 Myr, employing transient boundary conditions derived from climate modelling and climate proxy records. We discuss the imprint of changing climate conditions, sea level and geothermal heat flux on the ice thickness, and basal conditions around previously identified sites with continuous records of old ice. Our modelling results show a range of configurational ice-sheet changes across the middle Pleistocene transition, suggesting a potential shift of the West Antarctic Ice Sheet to a marine-based configuration. Despite the middle Pleistocene climate reorganisation and associated ice-dynamic changes, we identify several regions conducive to conditions maintaining 1.5 Myr (million years) old ice, particularly around Dome Fuji, Dome C and Ridge B, which is in agreement with previous studies. This finding strengthens the notion that continuous records with such old ice do exist in previously identified regions, while we are also providing a dynamic continental ice-sheet context.