NSFGEO-NERC Pliocene Sea Level Amplitudes (PLIOAMP)

NSFGEO-NERC 上新世海平面振幅 (PLIOAMP)

• 批准号: 2035080
• 负责人: Robert DeConto
• 金额: $ 29.5万
• 依托单位: University of Massachusetts Amherst
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2035080&HistoricalAwards=false
• 关键词: NSFGEO; NERC; Pliocene; Sea; Level

This project is jointly funded by the National Science Foundation’s Directorate of Geosciences (NSF/GEO) and the Natural Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own component of the work. Projections of future sea-level rise from the Antarctic Ice Sheet vary widely and remain deeply uncertain. Of particular concern is the potential for marine-based sectors of the ice sheet to collapse and cause fast sea-level rise. The highest future sea-level projections come from a study that calibrated an ice-sheet model using sea-level data from the Pliocene epoch (5.3 to 2.6 Million years ago), based mainly on the elevation of ancient shorelines. However, recent work indicates that those former shorelines are too uncertain to be used as a model constraint. Independent and better-constrained estimates of Pliocene sea level are needed to determine ice-sheet sensitivity to climatic conditions warmer than today and to validate models used in future projections. This project aims to achieve that through reconstructing the amplitude of polar ice-volume change from proxy data recorded in marine sediments and then using these to validate and assess ice-sheet modeling approaches that simulate ice-volume change. The aims of the project are to 1) improve Pliocene sea-level estimates, 2) use the data to test and calibrate predictive ice-sheet models, and 3) to reduce uncertainty in future sea-level projections. The proposed workplan will determine if there was major retreat of the marine sectors of the Antarctic Ice Sheet during Pliocene warm intervals, and if processes capable of causing rapid sea-level rise such as marine-ice cliff failure are indeed required to explain past episodes of elevated sea level. The work plan will 1) reconstruct the amplitude of ice-volume change for multiple glacial-interglacial cycles during the mid-Pliocene using marine geochemical proxies, 2) simulate ice-volume change across these same cycles for both Antarctic and Northern Hemisphere ice sheets, 3) compare Antarctic ice sheet change in two models using parameterized and resolved grounding-line schemes, and 4) determine if marine ice-cliff failure is required to simulate the Pliocene dynamics. The new sea-level estimates will constrain Antarctic simulations under future climate change, producing projections of future sea level rise on century and longer timescales.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.

该项目由国家科学基金会地球科学理事会（NSF/GEO）和联合王国自然环境研究理事会（NERC）通过NSF/GEO-NERC牵头机构协议共同资助。该协议允许美国/英国提交一份联合提案，并由研究者拥有最大预算比例的机构进行同行评审。在成功联合确定授标后，每个机构为预算的一部分和与本机构工作有关的调查员提供资金。 对南极冰盖未来海平面上升的预测差异很大，仍然非常不确定。特别令人关切的是，冰盖的海洋部分有可能崩溃，导致海平面迅速上升。未来最高海平面预测来自一项研究，该研究使用上新世（530万至260万年前）的海平面数据校准了冰盖模型，主要基于古代海岸线的海拔。然而，最近的工作表明，这些以前的海岸线是太不确定，不能作为一个模型的约束。需要对上新世海平面进行独立和更好的约束估计，以确定冰盖对比今天更温暖的气候条件的敏感性，并验证未来预测中使用的模型。 该项目旨在通过从海洋沉积物中记录的代理数据重建极地冰量变化的幅度，然后使用这些数据来验证和评估模拟冰量变化的冰盖建模方法来实现这一目标。 该项目的目标是：1）改善上新世海平面估计，2）使用数据来测试和校准预测冰盖模型，3）减少未来海平面预测的不确定性。拟议的工作计划将确定在上新世温暖时期南极冰盖的海洋部分是否有大的退缩，以及是否确实需要能够导致海平面快速上升的过程，如海冰悬崖断裂，来解释过去海平面上升的事件。该工作计划将：1）使用海洋地球化学代用指标重建上新世中期多个冰川-间冰期循环的冰量变化幅度，2）模拟南极和北方半球冰盖在这些相同循环中的冰量变化，3）使用参数化和分解的接地线方案比较两个模型中的南极冰盖变化，（4）确定是否需要海洋冰崖破坏来模拟上新世动力学。新的海平面估计将限制南极洲在未来气候变化下的模拟，产生对未来海平面上升的预测，在世纪和更长的时间尺度上。这一奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

项目成果

Iceberg Calving: Regimes and Transitions

冰山崩解：制度和转变

• DOI: 10.1146/annurev-earth-032320-110916
• 发表时间: 2023
• 期刊: Annual Review of Earth and Planetary Sciences
• 影响因子: 14.9
• 作者: Alley, R.B.;Cuffey, K.M.;Bassis, J.N.;Alley, K.E.;Wang, S.;Parizek, B.R.;Anandakrishnan, S.;Christianson, K.;DeConto, R.M.
• 通讯作者: DeConto, R.M.

Keeping an Eye on Antarctic Ice Sheet Stability

• DOI: 10.5670/oceanog.2019.117
• 发表时间: 2019-03
• 期刊: Oceanography
• 影响因子: 2.8
• 作者: C. Escutia;R. DeConto;R. Dunbar;L. De Santis;A. Shevenell;Timothy Nash

The Paris Climate Agreement and future sea-level rise from Antarctica

• DOI: 10.1038/s41586-021-03427-0
• 发表时间: 2021-05-06
• 期刊: NATURE
• 影响因子: 64.8
• 作者: DeConto, Robert M.;Pollard, David;Dutton, Andrea
• 通讯作者: Dutton, Andrea

Reconciling persistent sub-zero temperatures in the McMurdo Dry Valleys, Antarctica, with Neogene dynamic marine ice-sheet fluctuations

协调南极洲麦克默多干谷持续零度以下的气温与新近纪动态海洋冰盖波动

• DOI: 10.1130/g49664.1
• 发表时间: 2022
• 期刊: Geology
• 影响因子: 5.8
• 作者: Halberstadt, Anna Ruth;Kowalewski, Douglas E.;DeConto, Robert M.
• 通讯作者: DeConto, Robert M.

The Influence of the Solid Earth on the Contribution of Marine Sections of the Antarctic Ice Sheet to Future Sea‐Level Change

固体地球对南极冰盖海洋部分对未来海平面变化的影响

• DOI: 10.1029/2021gl097525
• 发表时间: 2022
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Yousefi, M.;Wan, J.;Pan, L.;Gomez, N.;Latychev, K.;Mitrovica, J. X.;Pollard, D.;DeConto, R. M.
• 通讯作者: DeConto, R. M.