CAREER: Tectonically dead but geomorphologically alive: Investigating the role of hard rocks as triggers of widespread, long-term landscape change in continent interiors

职业：构造上已死，但地貌上却还活着：研究硬岩作为大陆内部广泛、长期景观变化的触发因素的作用

• 批准号: 2340311
• 负责人: Pedro Val
• 金额: $ 75.05万
• 依托单位: CUNY Queens College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-04-01 至 2029-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2340311&HistoricalAwards=false
• 关键词: CAREER; Tectonically; dead; but; geomorphologically

Though seemingly static to humans, watersheds – and the river networks they host – gradually and/or abruptly change configuration, growing, shrinking, and even disappearing over timescales of thousands to millions of years. River network reorganizations have remained enigmatic staples of landscapes in the interiors of continents for over a century. When far from any active geologic faults, little is known about what triggers them, how frequently they initiate, or how fast they evolve. In this project, the principal investigator will evaluate the hypothesis that resistant rocks near the outlets of rivers trigger and regulate the widespread river network reorganization in continent interiors. As human societies depend on water to develop and thrive, constraining the underlying regulators of past, current, and future distributions of rivers is fundamental to understanding the availability and sustainability of water resources on the Earth’s surface and subsurface. Through this project’s discoveries, the principal investigator will create an immersive, collaborative teaching initiative to train a diverse group of undergraduate and graduate students in topics and techniques of high environmental relevance. The work will foster the integration of scientific knowledge in higher education in the US, Brazil, and in collaborating high schools of the New York Metro area.Despite being in tectonically dead settings, landscapes in continent interiors are rife with evidence of drainage network reorganization and ongoing topographic change. Currently, no unifying mechanism systematically explains the spatial distribution, magnitudes, modes, and timing of drainage divide migration and river capture events in those landscapes. This research project will mechanistically link (i) rates of drainage divide migration and (ii) frequency-magnitudes of river capture events to lithologic changes of up to hundreds of kilometers downstream. The principal investigator’s research group will (i) constrain drainage area exchange rates between large neighboring drainage basins of the tectonically dead eastern Paraná Basin in southeast Brazil using cosmogenic nuclides, (ii) directly link those rates to basin-pair differences in rock properties (i.e. rock erodibilities, tensile, and compressive strengths), and (iii) integrate the empirical evidence with numerical modeling of landscape evolution using the Landlab library. Using this integrated Field + Laboratory + Numerical Modeling triad, the research results will systematically explain rates of drainage reorganization in continent interiors independent of external, hard-to-constrain triggers. Τhe project will also create a seamless doorway between scientific discovery and undergraduate education through accessible, scaffolded training opportunities in Quantitative Geomorphology. The activities will inspire and empower the participating, underrepresented student populations to tackle environmental challenges.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.

尽管对人类来说，流域及其河流网络似乎是静态的，但在数千到数百万年的时间尺度内，流域及其所在的河流网络逐渐和/或突然改变配置、增长、缩小甚至消失，河流网络的重组仍然是地貌中神秘的主要部分。当远离任何活跃的地质断层时，人们对它们的触发因素、它们发生的频率或它们的演化速度知之甚少。在这个项目中，首席研究员将评估这一假设。河流出口附近的岩石触发并调节大陆内部广泛的河网重组，由于人类社会依赖水来发展和繁荣，限制河流过去、当前和未来分布的潜在调节因素对于了解河流的可用性和分布至关重要。通过该项目的发现，首席研究员将创建一项沉浸式协作教学计划，以培养多元化的本科生和研究生群体，使其掌握与环境高度相关的主题和技术。整合美国、巴西和纽约都会区合作高中的科学知识。尽管处于构造上死亡的环境中，大陆内部的景观却充满了排水网络重组和持续地形变化的证据。没有统一的机制系统地解释这些景观中排水沟迁移和河流捕获事件的空间分布、规模、模式和时间。该研究项目将机械地将（i）排水沟迁移速率和（ii）联系起来。首席研究员的研究小组将（i）利用宇宙成因核素限制巴西东南部构造死亡的巴拉那盆地东部大型流域之间的流域面积交换率。 ，（ii）将这些速率与岩石性质（即岩石可蚀性、拉伸和压缩强度）的盆地对差异直接联系起来，以及（iii）将经验证据与数值相结合使用 Landlab 库对景观演化进行建模。使用这种集成的现场 + 实验室 + 数值建模三元组，研究结果将系统地解释独立于外部、难以约束的触发因素的大陆内部的排水重组率。通过定量地貌学方面的便捷、支架式培训机会，在科学发现和本科教育之间建立无缝衔接。这些活动将激励和授权参与的、代表性不足的学生群体应对环境挑战。该奖项反映了 NSF 的法定使命，并具有通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。