Bounding global ice volumes over the last glacial cycle using reconstructions of Bering Strait flooding

使用白令海峡洪水重建来限制上一个冰川周期的全球冰量

• 批准号: 2054757
• 负责人: Tamara Pico
• 金额: $ 32.08万
• 依托单位: University of California-Santa Cruz
• 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: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2054757&HistoricalAwards=false
• 关键词: Bounding; global; ice; volumes; over

The stability of Earth’s ice sheets in the past informs our understanding of their resilience in the face of a warming climate. Knowing the magnitude and timing of global ice sheet changes is important for understanding how past ice sheet change related to climate change. However, we know little about how dynamic ice sheets were prior to 26,000 years ago, when ice sheets were at their largest. This project will use new geochemical tools to tell when the Bering Strait was flooded or exposed during the last glacial cycle (the past 120,000 years). In combination with computer model simulations, this information will be used to bound previously unknown global ice volume histories over this time. Further, this project will support a PhD student, who will learn about how science can produce social inequities through the UC Santa Cruz Science & Justice Research Center. PI Pico will develop innovative teaching tools for making legible the roots of geoscience culture in scientific racism and imperialism. These tools will be included in courses taught at UC Santa Cruz and Princeton. Finally, all personnel will participate in the outreach to the Alaska Native Science & Engineering Program.The history of global ice sheet growth leading into the Last Glacial Maximum is poorly constrained, as advancing ice sheets and subsequent sea-level rise during deglaciation destroyed evidence of past ice margins and coastlines. To address this uncertainty, this project will develop a continuous, non-traditional sea-level reconstruction over the last glacial cycle (120,000 years) by constraining the flooding history of the Bering Strait. Measuring nitrogen isotope ratios of organic matter protected within the shell walls of Arctic planktic foraminifera will elucidate the past connectivity of the North Pacific and Arctic Oceans, thus constraining the local sea-level history at the Bering Strait. State-of-the-art glacial isostatic adjustment sea-level simulations will be performed using the range of uncertainty on global ice volumes to model local sea level at the Bering Strait. Finally, this continuous Bering Strait flooding reconstruction will be used to test the plausibility of different global ice volume histories, and thus bound global mean sea-level highstands and lowstands before the Last Glacial Maximum.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.

过去地球冰盖的稳定性有助于我们了解其在气候变暖时的恢复能力，了解全球冰盖变化的幅度和时间对于了解过去冰盖变化与气候变化的关系非常重要。我们对 26,000 年前冰盖的动态情况知之甚少，当时冰盖最大。该项目将使用新的地球化学工具来判断白令海峡在上一次冰川周期（过去的冰川周期）何时被淹没或暴露。结合计算机模型模拟，该信息将用于确定这一时期以前未知的全球冰量历史。此外，该项目还将支持一名博士生，他将了解科学如何通过科学产生社会不平等。加州大学圣克鲁斯分校科学与司法研究中心。 PI Pico 将开发创新的教学工具，以明确科学种族主义和帝国主义中地球科学文化的根源。参与阿拉斯加原住民科学与工程计划的推广。导致末次盛冰期的全球冰盖增长的历史受到了很少的限制，因为冰川消融期间冰盖的前进和随后的海平面上升破坏了过去冰缘和海岸线的证据。为了解决这一不确定性，该项目将通过测量白令海峡的洪水历史，对上一个冰川周期（12万年）进行连续的、非传统的海平面重建。北极浮游有孔虫壳壁内受保护的有机物将阐明北太平洋和北冰洋过去的连通性，从而限制白令海峡当地最先进的冰川均衡调整海平面的历史。将利用全球冰量的不确定性范围来模拟白令海峡的当地海平面，最后，这种连续的白令海峡洪水重建将用于测试不同全球冰量的合理性。该奖项反映了 NSF 的法定使命，并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，被认为值得支持。