CAREER: Unlocking the Isotopic Signatures of Weathering Recorded in Rivers Through Isotope-Enabled Reactive Transport

职业：通过同位素反应传输解锁河流中记录的风化的同位素特征

基本信息

批准号：
2047318
负责人：
Jennifer Druhan
金额：
$ 51.58万
依托单位：
University of Illinois at Urbana-Champaign
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-06-01 至 2026-05-31
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2047318&HistoricalAwards=false
关键词：
CAREER Unlocking Isotopic Signatures Weathering

项目摘要

The percolation of water through the shallowest layers of the solid Earth is vital to sustaining life on this planet. Moisture delivered to soil irrigates the crops we grow and sustains natural ecosystems. Water that reaches further into the subsurface recharges aquifers and supplies the baseflow to streams and rivers. This transit through the shallow Earth also introduces water as a reactive agent capable of weathering the minerals that compose the crust, allowing chemical transformations that convert rock to soil and set the chemical signature of water resources. Thus, water is an integrator of this “critical zone”, i.e., the surface of the Earth where we live and draw resources. Such vital transformations are largely hidden from direct study because they occur below our feet in the near surface. Thus, we rely upon models that describe the rates and pathways of fluid drainage through the critical zone, coupled to the chemical reactions that occur between water, minerals and life, to predict what takes place where we cannot make direct observations. These models are then checked against more accessible samples often using the chemistry of streams and rivers which drain watersheds. Using novel instrumentation and model development, this project will offer the first direct validation of these reactive transport models based on fluids and solids collected within the transition from soil to stream. The broader impacts of this study include the improvement of predictive models for the chemical signatures of water quality and critical zone functioning. The capability to develop and deploy such models is vital to the advancement of watershed management and critical zone science. In pursuit of this goal, the project will create an open access online training platform designed to educate the next generation of Earth scientists in the development of state-of-the-art reactive transport models. The teaching modules will be deployed as part of an NSF-RCN award and will feature ADA-compliant web design with both self-guided and classroom integration options. This resource will foster the expanded use and equitable availability of next generation quantitative models and promote international collaborations across the global critical zone community.Predictive models for the tight coupling between fluid transport and chemical reactivity in critical zone weathering profiles remain largely validated against easily accessible observations such as the fluids that emerge as spring water and baseflow to streams and rivers. These integrated signatures of fluid draining landscapes offer a vital means of testing forward models and an increasing emphasis is now being placed on the use of riverine stable isotope ratios (e.g., 7Li, 30Si, 27Mg, 44Ca) for their exquisite sensitivity to specific components of chemical weathering. Integration of these promising tools into reactive transport simulations could hold the key to high fidelity predictive models for the coupling of chemistry and fluid flow draining intact weathering profiles. This proposal will generate three major advancements towards this goal: (1) quantitative interpretation of solute isotope signatures as a function of fluid travel time; (2) validation of isotope signatures in the zone of weathering between infiltration and discharge; and (3) predictive models for the weathering processes recorded by the isotope ratios of rivers draining watersheds. This will be accomplished through leveraging of a series of laboratory column experiments designed to support model development and in turn application to a novel field-scale instrumentation capability which allows direct collection of fluid samples in the partially saturated section of the critical zone where fluid drains through regolith before emerging as the baseflow to streams. The results of this work will test a set of hypotheses that link theory to observations of isotope ratios in the solutes derived from chemical weathering.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.

水穿过固体地球最浅层的渗透对于维持地球上的生命至关重要。输送到土壤的水分可以灌溉我们种植的农作物，并维持自然生态系统。深入地下的水可以补给含水层，并为溪流提供基流。这种穿越地球浅层的过程还引入了水作为反应剂，能够风化构成地壳的矿物质，从而发生化学变化，将岩石转化为土壤，并形成水资源的化学特征。因此，水是这个“关键区域”的整合者，即我们居住和获取资源的地球表面，这种重要的转变在很大程度上无法直接研究，因为它们发生在我们脚下的近地表。这些模型描述了通过关键区域的液体排出的速率和路径，与水、矿物质和生命之间发生的化学反应相结合，以预测在我们无法直接观察的情况下会发生什么，然后经常根据更容易获得的样本来检查这些模型。利用溪流的化学作用和该项目将使用新颖的仪器和模型开发，基于从土壤到河流的过渡过程中收集的流体和固体，对这些反应性传输模型进行首次直接验证。开发和部署此类模型的能力对于流域管理和关键区域科学的进步至关重要。为了实现这一目标，该项目将创建一个开放的在线培训平台。旨在教育下一代地球科学家最先进的反应式运输模型的开发将作为 NSF-RCN 奖项的一部分进行部署，并将采用符合 ADA 的网页设计，并提供自学和课堂集成选项。扩大下一代模型的定量使用和公平可用性，并促进全球关键区域界的国际合作。关键区域风化剖面中流体传输和化学反应性之间紧密耦合的预测模型仍然在很大程度上根据易于获取的观测结果（例如流体）进行验证以泉水的形式出现，这些流体排水景观的综合特征提供了测试正演模型的重要手段，并且现在越来越重视河流稳定同位素比率的使用（例如，7Li、30Si、27Mg、）。 44Ca）对化学风化的特定成分具有极高的敏感性，将这些有前途的工具集成到反应输运模拟中可能是高保真度预测模型的关键。该提案将为实现这一目标带来三个重大进展：（1）将溶质同位素特征定量解释为流体传播时间的函数；（2）验证同位素特征。渗透和排放之间的风化区；（3）通过排水流域的河流同位素比率记录的风化过程的预测模型这将通过利用设计的一系列实验室柱实验来完成。支持模型开发并反过来应用于新型现场规模仪器功能，该功能允许在关键区域的部分饱和部分直接收集流体样本，在该区域中，流体在作为基流出现之前会通过风化层排出，从而测试一组流体。将理论与化学风化所得溶质中同位素比率的观察联系起来的假设。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。

项目成果

期刊论文数量（5）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Subsurface weathering signatures in stream chemistry during an intense storm

强烈风暴期间河流化学中的地下风化特征

DOI：
10.1016/j.epsl.2022.117773
发表时间：
2022-10
期刊：
Earth and Planetary Science Letters
影响因子：
5.3
作者：
Golla, Jon K.;Bouchez, Julien;Kuessner, Marie L.;Rempe, Daniella M.;Druhan, Jennifer L.
通讯作者：
Druhan, Jennifer L.

The evolution of lithium isotope signatures in fluids draining actively weathering hillslopes

活跃风化山坡排水液中锂同位素特征的演变

DOI：
10.1016/j.epsl.2021.116988
发表时间：
2021-08-01
期刊：
Earth and Planetary Science Letters
影响因子：
5.3
作者：
Jon K. Golla;M. Kuessner;M. Henehan;J. Bouchez;D. Rempe;J. Druhan
通讯作者：
J. Druhan

Resiliency of Silica Export Signatures When Low Order Streams Are Subject to Storm Events

当低阶流遭受风暴事件时二氧化硅出口签名的弹性

DOI：
10.1029/2021jg006660
发表时间：
2022-04-25
期刊：
Journal of Geophysical Research: Biogeosciences
影响因子：
0
作者：
N. Fern;ez;ez;J. Bouchez;L. Derry;J. Chorover;J. Gaillardet;I. Giesbrecht;D. Fries;J. Druhan
通讯作者：
J. Druhan

Weathering Incongruence in Mountainous Mediterranean Climates Recorded by Stream Lithium Isotope Ratios

通过溪流锂同位素比记录地中海山区气候的风化不一致