NSFPLR-NERC: Geological history constraints on the magnitude of grounding line retreat in the Thwaites Glacier system

NSFPLR-NERC：地质历史对思韦茨冰川系统接地线后退幅度的限制

• 批准号: NE/S00663X/1
• 负责人: John Woodward
• 金额: $ 13.28万
• 依托单位: Northumbria University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FS00663X%2F1
• 关键词: NSFPLR; NERC; Geological; history; constraints

We propose to obtain geological evidence from the Thwaites-Pine Island glacier system that will show whether glaciers were less extensive than they are at present, and, if so, when. Our goals are to: (i) determine whether previous grounding-line retreat-advance cycles, as suggested by existing geological evidence, occurred in the late Holocene, and (ii) establish under what climate and sea-level boundary conditions they took place. Determining the conditions under which the Thwaites and Pine Island Glacier grounding lines have retreated and re-advanced in the past is critically relevant to determining whether or not present-day grounding-line retreat is irreversible.We will utilize two approaches to achieve these goals. To obtain geological evidence for past grounding-line retreat episodes, we will apply cosmogenic-nuclide exposure-dating of subglacial bedrock. Using drill systems recently developed in the USA for subglacial bedrock recovery and proven in the 2016-17 Antarctic field season, we will obtain subglacial bedrock from sites where ice thickness is dynamically linked to grounding line position in the Thwaites system. The observation of significant cosmogenic-nuclide concentrations in these samples would provide direct, unambiguous evidence for past episodes of thinning linked to grounding line retreat as well as constraints on their timing and duration. To reconstruct Holocene relative sea level, we will map and date raised marine and shoreline deposits throughout Pine Island Bay.

我们建议从斯威特-派恩岛冰川系统中获得地质证据，以表明冰川是否比现在更小，如果是的话，什么时候。我们的目标是：（i）确定现有地质证据所表明的先前的接地线后退-前进周期是否发生在全新世晚期，以及（ii）确定它们发生在什么气候和海平面边界条件下。确定斯韦茨冰川和松岛冰川接地线在过去后退和再前进的条件，对于确定目前的接地线后退是否不可逆转至关重要。我们将利用两种方法来实现这些目标。为了获得过去的地面线后退事件的地质证据，我们将应用宇宙成因核素测年的冰下基岩。使用最近在美国开发的用于冰下基岩恢复并在2016-17南极野外季节得到证明的钻探系统，我们将从冰厚度与Thwaites系统中接地线位置动态相关的地点获得冰下基岩。在这些样本中观测到显著的宇宙成因核素浓度，将为过去与接地线后退有关的变薄事件及其时间和持续时间的限制提供直接、明确的证据。为了重建全新世相对海平面，我们将绘制整个松岛湾的海洋和海岸线沉积物的地图和日期。

项目成果

Offshore-onshore record of Last Glacial Maximum–to–present grounding line retreat at Pine Island Glacier, Antarctica

南极洲松岛冰川末次盛冰期至目前接地线退缩的近海-陆上记录

• DOI: 10.1130/g51326.1
• 发表时间: 2023
• 期刊: Geology
• 影响因子: 5.8
• 作者: Nichols, Keir A.;Rood, Dylan H.;Venturelli, Ryan A.;Balco, Greg;Adams, Jonathan R.;Guillaume, Louise;Campbell, Seth;Goehring, Brent M.;Hall, Brenda L.;Wilcken, Klaus
• 通讯作者: Wilcken, Klaus

Stability of the Antarctic Ice Sheet during the pre-industrial Holocene

• DOI: 10.1038/s43017-022-00309-5
• 发表时间: 2022-07
• 期刊: Nature Reviews Earth & Environment
• 影响因子: 42.1
• 作者: Richard S. Jones;Joanne S. Johnson;Yucheng Lin;A. Mackintosh;J. Sefton;James A. Smith;E. Thomas;P. Whitehouse

Geological insights from the newly discovered granite of Sif Island between Thwaites and Pine Island glaciers

思韦茨冰川和松岛冰川之间新发现的锡夫岛花岗岩的地质见解

• DOI: 10.1017/s0954102023000287
• 发表时间: 2024
• 期刊: Antarctic Science
• 影响因子: 1.6
• 作者: Marschalek, James W.;Thomson, Stuart N.;Hillenbrand, Claus-Dieter;Vermeesch, Pieter;Siddoway, Christine;Carter, Andrew;Nichols, Keir;Rood, Dylan H.;Venturelli, Ryan A.;Hammond, Samantha J.
• 通讯作者: Hammond, Samantha J.

A decade of in situ cosmogenic 14C in Antarctica

南极洲原位宇宙生成 14C 的十年

• DOI: 10.31223/x5m369
• 发表时间: 2023
• 作者: Nichols K

Review article: Existing and potential evidence for Holocene grounding-line retreat and readvance in Antarctica

• DOI: 10.5194/tc-2021-360
• 发表时间: 2021-12
• 作者: Joanne S. Johnson;R. Venturelli;G. Balco;C. Allen;S. Braddock;S. Campbell;B. Goehring;B. Hall;P. Neff;K. Nichols;D. Rood;E. Thomas;J. Woodward