Collaborative Research: P2C2: Holocene glacier length variations along the spine of the American Cordilleras and their climatic significance

合作研究：P2C2：沿美洲科迪勒拉山脉脊柱的全新世冰川长度变化及其气候意义

• 批准号: 1805620
• 负责人: Jeremy Shakun
• 金额: $ 7.86万
• 依托单位: Boston College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1805620&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; Holocene; glacier

The worldwide retreat of glaciers over the past century is one of the clearest signals of global warming, but it raises two basic questions that remain hazy: how anomalous are current glacier extents, and what were long-term glacier trends prior to the industrial era? This project will reconstruct how often during the Holocene (the last 11,000 years) a dozen glaciers down the length of the Americas, from the Arctic to Patagonia, were larger versus smaller than today. We take a community-based approach to reduce cost, with active glacier scientists collecting samples gratis during their own field campaigns to contribute to this project. Our results will provide a geologic lens through which to view modern climate change, and offer a paleo-test for computer models used to simulate glacier responses to future warming -- important to freshwater resources in some areas and global sea level rise. We will reconstruct glacier histories by applying the in situ 14C-10Be chronometer to several samples of proglacial bedrock at each glacier terminus. This technique is able to determine what portion of the Holocene a glacier advanced beyond and retreated behind its current terminus by quantifying the buildup of both 14C and 10Be during periods of exposure and the preferential loss of 14C during episodes of ice cover due to its much shorter half-life. Our latitudinal transect is designed to maximize understanding of how glaciers responded to orbital variations, as well as how climate may have been coupled between the low and high latitudes and across the hemispheres. Given that Holocene glacier trends may have varied substantially with latitude, the broad scale of our reconstructions will also provide the context needed for evaluating current glacier retreat around the world.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.

在过去的一个世纪中，全球冰川的撤退是全球变暖的最明显信号之一，但它提出了两个基本问题，这些问题仍然是朦胧的：目前的冰川范围是如何异常的，工业时代之前的长期冰川趋势是什么？该项目将重建全新世（过去11，000年）的频率，从北极到巴塔哥尼亚的美洲长度降低了十二个冰川，比今天更小。我们采用一种基于社区的方法来降低成本，活跃的冰川科学家在自己的现场活动中收集样本，以为该项目做出贡献。我们的结果将提供一个地质镜头，可以通过该镜头来查看现代气候变化，并为用于模拟对未来变暖的冰川响应的计算机模型提供古测试 - 对某些地区的淡水资源和全球海平面上升至关重要。我们将通过将原位14C-10BE的计时仪施加到每个冰川末端的几个前冰期基岩样本中来重建冰川历史。该技术能够通过量化暴露期间的14C和10BE的堆积，并在冰盖发作期间量化14C和10BE的堆积，从而确定全新世的哪一部分，并通过量化14C和10BE的堆积，原因是其当前末端，并在其当前末端撤退。我们的纬度样品旨在最大程度地了解冰川对轨道变化的反应，以及在低纬度和高纬度之间以及整个半球之间的气候如何耦合。鉴于全新世冰川趋势可能与纬度有很大不同，因此我们重建的广泛规模还将提供评估世界各地当前冰川静修所所需的背景。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子和更广泛影响的评估来审查的审查标准，这是值得通过评估的支持。

项目成果

Similar Holocene glaciation histories in tropical South America and Africa

• DOI: 10.1130/g48059.1
• 发表时间: 2021-02
• 期刊: Geology
• 影响因子: 5.8
• 作者: A. Vickers;J. Shakun;B. Goehring;A. Gorin;M. Kelly;M. Jackson;A. Doughty;J. Russell