CAREER: Quantifying climate induced landscape evolution during early Eocene hyperthermals

职业：量化始新世早期高温期间气候引起的景观演化

• 批准号: 2237624
• 负责人: Emily Beverly
• 金额: $ 79.6万
• 依托单位: University of Houston
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-02-01 至 2028-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2237624&HistoricalAwards=false
• 关键词: CAREER; Quantifying; climate; induced; landscape

The US has incurred billions of dollars in damage from extreme precipitation events linked to anthropogenic climate change since the 1980s. Increased erosion and sediment yield from these events is likely to damage soils, clog rivers, and cripple hydraulic infrastructure. However, we have little information on the magnitude of the response of our rivers and landscapes to global climate change because these changes occur on timescales difficult to measure in our lifetimes. Therefore, we must look to times in Earth’s past when temperatures and atmospheric CO¬2 concentrations rose rapidly to study landscape response. During the early Eocene, approximately 56 to 52 million years ago, there were repeated intervals known as hyperthermal events where global temperatures rapidly increased due to releases of CO2 over a period of ~20,000 years. These hyperthermals provide one of the best analogs to modern anthropogenic climate change, albeit at a slower rate than today. This project will focus on improving scientific and public understanding of how future climate change will affect our river systems by using analogs from the early Eocene in New Mexico, Wyoming, and North Dakota. The education plan will target a diverse population of students from the University of Houston that will strengthen undergraduate exposure to field geology using virtual field trips. Because climate change can be an abstract and intimidating concept for some groups, collaborations with a world-renowned climate-artist will be used to break down mental barriers and communicate science to the public and low-income and minority students from the Houston area. This project will generate new terrestrial paleoclimate records from three fluvially dominated basins in the western US: 1) San Juan Basin of New Mexico, 2) Wind River Basin of Wyoming, and 3) Williston Basin of North Dakota. It will use a novel method that integrates datasets from both sandstone channel facies and floodplain paleosols to test the hypothesized connection between hyperthermal-driven hydrologic cycle intensification and increased weathering that formed large sand bodies and thick packages of kaolinite. This project will use a multi-proxy approach that includes geochemistry, mineralogy, stable isotopes (δ13C, δ18O, and Δ47), sedimentology, stratigraphy, radiogenic isotope geochronology (40Ar/39Ar, U-Th-Pb), and magnetostratigraphy to reconstruct the paleoclimate and constrain landscape response to the hyperthermal events both spatially and temporally. The resulting dataset will be integrated into quantitative models to test how rapid atmospheric CO2 increases, global warming, and the resulting hydrologic cycle intensification will increase the magnitude of weathering and sediment yield, which has the potential to cause billions of dollars in damage to infrastructure and ecosystems from soil loss, erosion, and increased flooding.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.

自20世纪80年代以来，与人为气候变化有关的极端降水事件给美国造成了数十亿美元的损失。这些事件增加的侵蚀和泥沙产量可能会破坏土壤，堵塞河流，并使水利基础设施瘫痪。然而，我们几乎没有关于我们的河流和景观对全球气候变化的反应程度的信息，因为这些变化发生在我们有生之年难以衡量的时间尺度上。因此，我们必须着眼于地球过去温度和大气二氧化碳浓度迅速上升的时期来研究景观响应。在约5600万至5200万年前的始新世早期，由于二氧化碳的释放，全球气温在约2万年的时间内迅速上升，出现了被称为超热事件的重复间隔。这些高温现象提供了现代人类活动气候变化的最佳类比之一，尽管其速度比今天慢。该项目将侧重于通过使用新墨西哥州、怀俄明州和北达科他州始新世早期的类比，提高科学和公众对未来气候变化将如何影响我们的河流系统的理解。这项教育计划将针对休斯顿大学的不同群体的学生，这将通过虚拟实地考察来加强本科生对野外地质的接触。由于气候变化对一些团体来说可能是一个抽象而可怕的概念，与世界知名的气候艺术家的合作将被用来打破心理障碍，向公众以及休斯顿地区的低收入和少数族裔学生传播科学。该项目将从美国西部三个以河流为主的盆地产生新的陆地古气候记录：1)新墨西哥州的圣胡安盆地，2)怀俄明州的风河盆地，3)北达科他州的威利斯顿盆地。它将使用一种新的方法，整合来自砂岩河道相和洪泛平原古土壤的数据集，以测试高温驱动的水文循环强化与形成大砂体和厚厚高岭石包的风化增加之间的假设联系。该项目将使用包括地球化学学、矿物学、稳定同位素(δ13C、δ18O和Δ47)、沉积学、地层学、放射性同位素年代学(40Ar/39Ar、U-Th-Pb)和磁性地层学的多种替代方法来重建古气候，并在空间和时间上限制景观对高温事件的响应。最终的数据集将被集成到定量模型中，以测试大气中二氧化碳的快速增加、全球变暖以及由此导致的水文循环强化将增加风化和沉积物产量的程度，这可能会因土壤流失、侵蚀和洪水增加而对基础设施和生态系统造成数十亿美元的损害。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。