Quantifying Climatic Control of Erosional Efficiency

侵蚀效率的量化气候控制

• 批准号: 0921705
• 负责人: Kelin Whipple
• 金额: $ 36.59万
• 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: 2009
• 资助国家: 美国
• 起止时间: 2009-08-15 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0921705&HistoricalAwards=false
• 关键词: Quantifying; Climatic; Control; Erosional; Efficiency

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Little is known quantitatively about the climatic control on erosion rates at millennial or longer timescales. Although details vary, landscape evolution models all predict a positive, monotonic relationship between river discharge and erosion rate. However, little data exists to support this fundamental expectation at the landscape scale due to the difficulty in isolating variables in large-scale natural systems. Indeed, some of the most convincing data available shows strong relationships between erosion rate and relief, but little or no significant correlation between mean annual precipitation and erosion rate. This research will test the hypothesis that mean annual precipitation strongly influences the efficiency of erosion, such that the functional relationship between relief and erosion rate will change systematically from arid to increasingly humid catchments underlain by the same rock type. Millennial-scale erosion rates will be determined via cosmogenic radionuclide measurements for a suite of catchments in six field sites distributed in different climatic settings, but with similar ranges of relief in similar bedrock. By comparing across sites, these data will quantify the relationship between mean annual precipitation and erosion rate.Few problems are more fundamental to shaping the Earth's surface than the relationship between climate and erosion. Consequently, the research questions pursued here have direct implications for problems of immediate societal relevance including climatic impacts on reservoir sedimentation rates, natural hazards, and rates of soil erosion. The role of climate in surface processes is equally central to fundamental problems in allied fields. For example, there is a great deal of interest in how climate controls silicate weathering rates, since this process extracts atmospheric carbon dioxide and thus acts to reduce the level of greenhouse gases. Erosion will affect the rate of silicate weathering, and, as such, will directly influence this removal of carbon dioxide. The difficulty of distinguishing climate from tectonic uplift in controlling sediment influx into basins has been a long-standing problem in the geological sciences. This research will provide new tools for gaining insight into this process.

该奖项是根据2009年的《美国回收与再投资法》（公共法第111-5号）资助的。在千禧一代或更长的时间表上对侵蚀率的气候控制的数量众所周知。 尽管细节有所不同，但景观演化模型都预测了河流排放与侵蚀率之间的正面关系。 但是，由于难以隔离大规模自然系统中的变量，因此很少有数据可以支持景观量表的基本期望。 确实，一些最令人信服的数据显示了侵蚀率和缓解率之间的牢固关系，但平均年降水量和侵蚀率之间的相关性很小或没有显着相关。这项研究将检验以下假设，即年度降水会强烈影响侵蚀的效率，以便浮雕与侵蚀速率之间的功能关系将从干旱系统中系统变化，从越来越多的潮湿的流域被相同的岩石类型所在。千禧一代侵蚀率将通过宇宙性放射性核素测量值确定，该测量值在不同气候环境中分布的六个场地的集水区套件，但在类似的基岩中具有相似的浮雕范围。 通过对跨站点进行比较，这些数据将量化平均年降水量和侵蚀率之间的关系。对塑造地球表面比气候与侵蚀之间的关系更为重要。 因此，这里提出的研究问题对直接社会相关性问题有直接影响，包括对储层沉积率，自然危害和土壤侵蚀率的气候影响。 气候在表面过程中的作用对于盟军领域的基本问题同样核心。例如，由于此过程提取大气二氧化碳，因此可以降低温室气体的水平，因此对气候控制硅化速率的方式引起了极大的兴趣。侵蚀将影响硅酸盐风化的速度，因此，将直接影响这种去除二氧化碳。将气候与构造隆升区分开控制沉积物涌入盆地的困难已成为地质科学的一个长期问题。这项研究将提供新的工具，以洞悉此过程。