Stratigraphy and chronology of IODP Exp. 374 (Ross Sea West Antarctic Ice Sheet History) drill cores: implications for West Antarctic glaciations

IODP 实验的地层学和年代学。

• 批准号: NE/R018235/1
• 负责人: Chuang Xuan
• 金额: $ 6.88万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FR018235%2F1
• 关键词: Stratigraphy; chronology; IODP; Exp.; 374

Over the past 55 million years, Earth's climate changed from a greenhouse into an icehouse world. Antarctica has been (partially) glaciated since ~34 million years ago. Initially, the Antarctic ice sheet probably grew to a larger size than it is at present-day. At present-day, however, the Antarctic continent is 'full' and the ice sheet cannot grow much larger anymore. Therefore the capacity of the Antarctic continent to store ice must have changed in the past. This has most likely happened in West Antarctica, where the ice sheet is now (shallow-)marine based, but is reconstructed to have been predominantly continental-based at its formation. The date of this change is currently unknown, and that is one of the key questions of this proposal: when did this so-called overdeepening occur?To address this question, this proposal will provide accurate age models for new cores, to be recovered from the Ross Sea (West Antarctica) in January-March 2018. These cores will also help with the evaluation of the instability of the West Antarctic ice sheet. A new climate model suggests that the West Antarctic ice sheet is not as stable as originally thought. This can result in global sea level of up to ~2 m by the end of this century, if we continue CO2 emissions under the business-as-usual scenario. The best way to evaluate this new model is by looking at its accuracy for past climates. Over the past millions of years, the size of the West Antarctic ice sheet has grown and shrunk due to climatic variations, which may be an analogy for future anthropogenic warming. In this proposal we will provide an accurate stratigraphy and age model for the recovered cores. We can then accurately reconstruct the size and position of the West Antarctic ice sheet and compare these to the predicted size and position from the model. Therefore, we can test the accuracy of the prediction that global sea levels will be up to ~2 m higher under business-as-usual CO2 emission scenarios.

在过去的5500万年里，地球气候从温室变成了冰窖世界。自约 3400 万年前以来，南极洲已经（部分）被冰川覆盖。最初，南极冰盖的尺寸可能比现在更大。然而，目前南极大陆已经“满了”，冰盖不能再变得更大了。因此，南极大陆储存冰的能力在过去一定发生了变化。这种情况很可能发生在南极洲西部，那里的冰盖现在以（浅）海洋为基础，但在形成时被重建为主要以大陆为基础。这种变化的日期目前尚不清楚，而这是该提案的关键问题之一：这种所谓的过度加深何时发生？为了解决这个问题，该提案将为2018年1月至3月从罗斯海（西南极洲）回收的新岩心提供准确的年龄模型。这些岩心还将有助于评估西南极冰盖的不稳定性。一个新的气候模型表明，西南极冰盖并不像最初想象的那么稳定。如果我们在一切照旧的情况下继续排放二氧化碳，到本世纪末，这可能会导致全球海平面上升约 2 m。评估这个新模型的最佳方法是查看其对过去气候的准确性。在过去的几百万年里，由于气候变化，西南极冰盖的大小不断增大和缩小，这可能是未来人为变暖的类比。在本提案中，我们将为回收的岩心提供准确的地层学和年龄模型。然后，我们可以准确地重建西南极冰盖的大小和位置，并将其与模型预测的大小和位置进行比较。因此，我们可以测试在二氧化碳排放照常的情况下全球海平面将升高约 2 m 的预测的准确性。

项目成果

Evaluation of geomagnetic relative palaeointensity as a chronostratigraphic tool in the Southern Ocean: Refined Plio-/Pleistocene chronology of IODP Site U1533 (Amundsen Sea, West Antarctica)

• DOI: 10.1016/j.quascirev.2023.108460
• 发表时间: 2024-02
• 期刊: Quaternary Science Reviews
• 影响因子: 4
• 作者: Becky Hopkins;Chuang Xuan;C. Hillenbrand;T. V. van Peer;Yuxi Jin;T. Frederichs;Liang Gao;S. Bohaty

Sensor Response Estimate and Cross Calibration of Paleomagnetic Measurements on Pass‐Through Superconducting Rock Magnetometers

穿过式超导岩石磁强计古地磁测量的传感器响应估计和交叉校准

• DOI: 10.1029/2019gc008597
• 发表时间: 2019
• 期刊: Geochemistry, Geophysics, Geosystems
• 作者: Xuan Chuang;Oda Hirokuni
• 通讯作者: Oda Hirokuni

A large West Antarctic Ice Sheet explains early Neogene sea-level amplitude

南极西部大冰盖解释了新近纪早期海平面振幅

• DOI: 10.1038/s41586-021-04148-0
• 发表时间: 2021
• 期刊: Nature
• 影响因子: 64.8
• 作者: Marschalek, J. W.;Zurli, L.;Talarico, F.;van de Flierdt, T.;Vermeesch, P.;Carter, A.;Beny, F.;Bout-Roumazeilles, V.;Sangiorgi, F.;Hemming, S. R.
• 通讯作者: Hemming, S. R.

Large obliquity-paced Antarctic ice-volume fluctuations suggest melting by atmospheric and ocean warming during late Oligocene

南极冰量的大倾角波动表明渐新世晚期大气和海洋变暖导致冰量融化

• DOI: 10.1038/s43247-023-00864-9
• 发表时间: 2023
• 期刊: Communications Earth & Environment
• 影响因子: 7.9
• 作者: Brzelinski S

New insights from multi-proxy data from the West Antarctic continental rise: Implications for dating and interpreting Late Quaternary palaeoenvironmental records

来自西南极洲大陆隆起的多代理数据的新见解：对晚第四纪古环境记录的年代测定和解释的启示

• DOI: 10.1016/j.quascirev.2021.106842
• 发表时间: 2021
• 期刊: Quaternary Science Reviews
• 影响因子: 4
• 作者: Hillenbrand C