West Antarctic Ice-sheet Change and Paleoceanography in the Amundsen Sea Across the Pliocene Climatic Optimum

上新世气候最适期西南极冰盖变化与阿蒙森海古海洋学

基本信息

批准号：
2114839
负责人：
Sandra Passchier
金额：
$ 41.06万
依托单位：
Montclair State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-08-15 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2114839&HistoricalAwards=false
关键词：
West Antarctic Ice sheet Change

项目摘要

The West Antarctic Ice Sheet is the most vulnerable polar ice mass to warming and already a major contributor to global mean sea level rise. Its fate in the light of prolonged warming is a topic of major uncertainty. Accelerated sea level rise from ice mass loss in the polar regions is a major concern as a cause of increased coastal flooding affecting millions of people. This project will disclose a unique geological archive buried beneath the seafloor off the Amundsen Sea, Antarctica, which will reveal how the West Antarctic Ice Sheet behaved in a warmer climate in the past. The data and insights can be used to inform ice-sheet and ocean modeling used in coastal policy development. The project will also support the development of a competitive U.S. STEM workforce. Online class exercises for introductory geology classes will provide a gateway for qualified students into undergraduate research programs and this project will enhance the participation of women in science by funding the education of current female Ph.D. students.The project targets the long-term variability of the West Antarctic Ice Sheet over several glacial-interglacial cycles in the early Pliocene sedimentary record drilled by the International Ocean Discovery Program (IODP) Expedition 379 in the Amundsen Sea. Data collection includes 1) the sand provenance of ice-rafted debris and shelf diamictites and its sources within the Amundsen Sea and Antarctic Peninsula region; 2) sedimentary structures and sortable silt calculations from particle size records and reconstructions of current intensities and interactions; and 3) the bulk provenance of continental rise sediments compared to existing data from the Amundsen Sea shelf with investigations into downslope currents as pathways for Antarctic Bottom Water formation. The results are analyzed within a cyclostratigraphic framework of reflectance spectroscopy and colorimetry (RSC) and X-ray fluorescence scanner (XRF) data to gain insight into orbital forcing of the high-latitude processes. The early Pliocene Climatic Optimum (PCO) ~4.5-4.1 Ma spans a major warm period recognized in deep-sea stable isotope and sea-surface temperature records. This period also coincides with a global mean sea level highstand of 20 m requiring contributions in ice mass loss from Antarctica. The following hypotheses will be tested: 1) that the West Antarctic Ice Sheet retreated from the continental shelf break through an increase in sub iceshelf melt and iceberg calving at the onset of the PCO ~4.5 Ma, and 2) that dense shelf water cascaded down through slope channels after ~4.5 Ma as the continental shelf became exposed during glacial terminations. The project will reveal for the first time how the West Antarctic Ice Sheet operated in a warmer climate state prior to the onset of the current “icehouse” period ~3.3 Ma.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

南极冰盖是最脆弱的极地冰块，已经是全球平均海平面上升的主要贡献者。鉴于长期变暖，其致命是一个主要不确定性的话题。极地地区的冰块质量损失加速的加速是一个主要问题，这是导致沿海洪水增加影响数百万人的原因。该项目将透露一个独特的地质档案馆，建于南极洲阿蒙森海附近的海底下，该档案将揭示西南极冰盖过去在温暖的气候中的表现。数据和见解可用于为沿海政策制定中使用的冰盖和海洋建模提供信息。该项目还将支持竞争激烈的美国STEM劳动力的发展。在线课程练习地质课程将为合格的学生提供一门进入本科研究计划的门户，该项目将通过资助现任女性博士学位的教育来增强妇女参与科学的参与。学生。该项目针对南极冰盖的长期变异性，比国际海洋发现计划（IODP）探险队在Amundsen Sea的早期上新世沉积记录中的几个冰川间冰期循环。数据收集包括1）在阿蒙森海和南极半岛地区，冰上碎屑和架子的碎屑及其来源的沙子出处； 2）从粒度记录和当前强度和相互作用的重建中的沉积结构和可排序的淤泥计算； 3）与Amundsen海架上的现有数据相比，连续上升沉积物的大部分出处是对下坡电流的研究，作为南极底部水形成的途径。在反射光谱和比色谱法（RSC）和X射线荧光扫描仪（XRF）数据的循环地层框架内分析结果，以深入了解高纬度过程的轨道强迫。早期上新世气候最佳（PCO）〜4.5-4.1 mA跨越了深海稳定同位素和海面温度记录中识别的主要温暖时期。这一时期还与全球平均海平面高台相吻合，为20 m，需要从南极洲造成的冰质量损失。将测试以下假设：1）从连续的冰片撤退的西部冰盖在PCO〜4.5 mA的开始时通过近距离融化和冰山产犊的增加而突破，而冰山产犊在PCO〜4.5 mA的开始和2）中，该架子的固定水通过sloteers consef slote consect terminate termine termine termine terminect extection terminate extect externe termination terminate extect extection。该项目将首次揭示在当前的“ Icehouse”时期开始之前，西南极冰盖如何在温暖的登山状态下运作〜3.3 MA。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和广泛的审查标准，通过评估诚实地认为通过评估。

项目成果

期刊论文数量（3）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

West Antarctic Ice Sheet Dynamics in the Amundsen Sea Sector since the Late Miocene?Tying IODP Expedition 379 Results to Seismic Data

晚中新世以来阿蒙森海区西南极冰盖动态？将 IODP 探险 379 结果与地震数据联系起来

DOI：
10.3389/feart.2022.976703
发表时间：
2022
期刊：
Frontiers in Earth Science
影响因子：
2.9
作者：
Gille-Petzoldt Johanna;Gohl Karsten;Uenzelmann-Neben Gabriele;Gr?tzner Jens;Klages Johann P.;IODP Expedition 379 Scientists
通讯作者：
IODP Expedition 379 Scientists

Pliocene Glacial-Interglacial Cyclicity in Sedimentation Offshore the Amundsen Sea, West Antarctica

南极洲西部阿蒙森海近海沉积物的上新世冰川-间冰期循环