Into the icehouse: Dramatic changes at the Devonian-Mississippian Climate Transition (DMCT)

进入冰库：泥盆纪-密西西比纪气候转变（DMCT）的巨大变化

• 批准号: 2241039
• 负责人: Ethan Grossman
• 金额: $ 58.61万
• 依托单位: Texas A&M University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-03-01 至 2026-02-28
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2241039&HistoricalAwards=false
• 关键词: Into; icehouse; Dramatic; changes; Devonian

Reconstructions of ancient ocean temperatures give important clues to the limits of future global warming, the causes of climate change, and the impact of climate change on biodiversity. This project will test whether tropical ocean temperatures were extremely warm (35-40 °C or 95-104 °F) during the time of early animals and examine the role of rapid cooling in triggering biotic crises. The study will also explore how climate change impacted the cycling of calcium and whether linkages between the calcium and carbon cycles play a role in climate change. Proxy data for paleoenvironments will be combined with sophisticated mass balance models to further test links between calcium, carbon dioxide, and climate. The project will broaden geochemical education through (1) training of three graduate students and members of underrepresented groups in cutting-edge techniques, (2) development of exercises and independent research projects for undergraduate and graduate classes, and (3) K-12 activities at the annual TAMU Chemistry Open House. The project will enhance research and education infrastructure by supporting two cutting-edge mass-spectrometry systems and by sharing the mass balance model framework.The project will feature clumped isotope paleothermometry, a recent advance that measures the co-occurrence of 13C and 18O in carbonate molecules (e.g., Ca13C18O16O2). Analyses will be performed on well-preserved brachiopod shells from North America (US and Canada) and Eastern Europe (Russia) spanning the Late Devonian to Early Mississippian (383 to 348 million years), a time of rapid climate and ocean chemistry change (“calcite” to “aragonite” seas), and multiple biological crises. Clumped isotope measurements will be combined with measurements of calcium, carbon, and oxygen isotopes and comprehensive numerical modeling to examine the interplay between calcium, carbon, and crustal cycling during this major climatic shift in Earth’s history and foster better understanding of the consequences of climate change in our near future.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.

对古代海洋温度的重建为未来全球变暖的极限、气候变化的原因以及气候变化对生物多样性的影响提供了重要线索。该项目将测试热带海洋温度在早期动物时期是否非常温暖（35-40 °C或95-104 °F），并研究快速冷却在引发生物危机中的作用。 该研究还将探讨气候变化如何影响钙的循环，以及钙和碳循环之间的联系是否在气候变化中发挥作用。古环境的代用数据将与复杂的质量平衡模型相结合，以进一步测试钙，二氧化碳和气候之间的联系。该项目将通过以下方式拓宽地球化学教育：（1）对三名研究生和代表性不足的群体成员进行尖端技术培训，（2）为本科生和研究生班开发练习和独立研究项目，以及（3）在每年的TAMU化学开放日开展K-12活动。该项目将通过支持两个先进的质谱系统和共享质量平衡模型框架来加强研究和教育基础设施。该项目将以聚集同位素古温度测量法为特色，这是一项最新进展，可以测量碳酸盐分子中13 C和18 O的共存（例如，Ca13C18O16O2）。将对来自北美（美国和加拿大）和东欧（俄罗斯）的保存完好的腕足动物外壳进行分析，时间跨度为晚泥盆纪至早密西西比纪（3.83亿至3.48亿年），这是一个气候和海洋化学变化迅速的时期（“方解石”到“文石”海），以及多次生物危机。聚集同位素测量将与钙、碳和氧同位素的测量以及综合数值模拟相结合，以研究钙、碳、和地壳循环在地球历史上的这一重大气候变化，并促进更好地了解气候变化的后果，在不久的将来。这个奖项反映了NSF的法定使命，并已被认为是值得支持，通过评估使用基金会的学术价值和更广泛的影响审查标准。