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Collaborative Research: Uplift or climate change? Determining the primary driver of deep canyon incision in the eastern cordillera, southern Peru

合作研究：抬升还是气候变化？

基本信息

批准号：
1842065
负责人：
Kelin Whipple
金额：
$ 25.26万
依托单位：
Arizona State University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-04-01 至 2024-03-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1842065&HistoricalAwards=false
关键词：
Collaborative Research Uplift climate change

项目摘要

Competition between the growth of new topography by tectonic uplift and erosion that wears it down occurs in many mountain regions. Earth scientists recognize that the ability of rivers to erode depends on how much water is delivered to the mountains, and that changes between wetter or dryer climates should influence topography. The expectation is that changes in climate and the resulting change in erosion are reflected in the topography of a landscape. This project focuses on the Eastern Cordillera of southern Peru, where deep canyons carved into the Central Andean Plateau margin reflect either tectonic uplift or an increase in erosional efficiency due to climate change. The research incorporates newly-developed methods for diagnosing the effects of climate on topography as part of a field-based investigation to determine the degree to which climate-driven changes in erosional efficiency are responsible for canyon cutting. New remote analysis methods are used to differentiate signatures of tectonic uplift driven erosion and climate driven erosion in topography. Improving the fidelity of these remote methods has considerable societal value because they are an inexpensive and efficient means of hazard assessment in areas where the presence or absence of tectonic uplift, and the resulting effect on seismicity, are uncertain. Additionally, this project wll benefit society by: 1) essential STEM training of three US graduate students including two women, as well as several Peruvian undergraduates; 2) international collaborations with both Peruvian and German universities; and 3) improved STEM education development in Peru and US at the undergraduate, graduate, and professional levels.Determination of an active tectonic driver of mountain uplift and the geometry of related structures is critical to resolving how strongly climate and tectonics are coupled. This project tests competing hypotheses for the proximal drivers of canyon cutting into the Eastern Cordillera: incision driven by active rock uplift vs. incision into a previously uplifted plateau margin triggered by climate change. Integration of observations and analyses of the deformation history, landscape morphology, precipitation patterns, and spatial and temporal patterns of erosion and exhumation is used to definitively and quantitatively evaluate the relative importance of active rock uplift and climate change in landscape evolution. Analyses focus on: 1. estimating millennial-scale erosion rates from cosmogenic 10Be concentrations in modern river sands, 2. assessing the role of rainfall in the relation between topography and erosion rate, 3. analyzing cooling ages of low-temperature thermochronometers (AHe, AFT, ZHe) provided by a complementary study, 4. refining geologic mapping and developing balanced cross sections, and 5. integrating all data in models to quantitatively test hypotheses. Results will have broad implications for: 1. the general applicability and fidelity of proposed methods for diagnosing the primary causes of canyon cutting based on analysis of geomorphic data, 2. further development of a methodology to quantitatively link geometry, displacement and rates on faults to exhumation rates, erosion rate patterns and the resulting landscape morphology, 3. quantitative, observation-based understanding of the sensitivity of erosion rates to annual rainfall, and 4. understanding of the nature and strength of linkages among climate, topography, erosion, and tectonics.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.

在许多山区，由于构造抬升而形成的新地形与侵蚀侵蚀形成的新地形之间存在着竞争。地球科学家认识到，河流侵蚀的能力取决于有多少水被输送到山区，而潮湿或干燥气候之间的变化应该会影响地形。人们期望，气候变化和由此产生的侵蚀变化反映在地形地貌上。该项目的重点是秘鲁南部的东科迪勒拉山脉，那里雕刻在安第斯高原中部边缘的深峡谷反映了构造隆升或气候变化导致的侵蚀效率增加。该研究采用了新开发的方法，用于诊断气候对地形的影响，作为实地调查的一部分，以确定气候驱动的侵蚀效率变化对峡谷切割的影响程度。采用新的遥感分析方法，区分地形上构造抬升驱动的侵蚀和气候驱动的侵蚀特征。提高这些远程方法的保真度具有相当大的社会价值，因为它们是一种廉价而有效的灾害评估手段，在这些地区，存在或不存在构造隆起，以及由此产生的对地震活动性的影响是不确定的。此外，该项目将通过以下方式造福社会：1）对三名美国研究生（包括两名妇女）和几名秘鲁本科生进行基本的STEM培训; 2）与秘鲁和德国大学进行国际合作;和3）改善秘鲁和美国本科生，研究生，确定山脉隆升的活跃构造驱动力和相关结构的几何形状，对于解决气候和构造耦合的强度至关重要。该项目测试了峡谷切入东科迪勒拉的近端驱动因素的相互竞争的假设：由活动岩石隆起驱动的切口与由气候变化引发的先前隆起的高原边缘的切口。整合的观测和分析的变形历史，景观形态，降水模式，以及空间和时间模式的侵蚀和剥露是用来确定性和定量评估的相对重要性，活动的岩石隆起和气候变化的景观演变。分析的重点是：1。估计千年尺度的侵蚀速率从宇宙成因10Be浓度在现代河砂，2。评估降雨在地形和侵蚀率之间关系中的作用，3.分析由补充研究提供的低温热计时器（AHe，AFT，ZHe）的冷却年龄，4.完善地质填图和开发平衡剖面;将所有数据整合到模型中，以定量检验假设。结果将有广泛的影响：1。基于地貌数据分析，诊断峡谷切割主要原因的建议方法的普遍适用性和保真度，2。进一步开发一种方法，将断层的几何形状、位移和速率与剥露速率、侵蚀速率模式和由此产生的景观形态定量联系起来，3.定量的，基于观测的了解侵蚀率的敏感性，年降雨量，和4。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。