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年美国复苏和再投资法案（公法111-5）资助的。 虽然细节不同，景观演变模型都预测河流流量和侵蚀率之间的正，单调的关系。 然而，很少有数据存在，以支持这一基本期望在景观尺度上，由于在大规模的自然系统中隔离变量的困难。 事实上，一些最有说服力的数据显示，侵蚀率和地形之间的关系很强，但很少或没有显着的相关性之间的平均年降水量和侵蚀率。这项研究将测试的假设，即年平均降水量强烈影响侵蚀的效率，这样的功能之间的关系，救济和侵蚀率将系统地改变从干旱到越来越潮湿的集水区由相同的岩石类型。千年尺度的侵蚀率将通过宇宙成因放射性核素测量确定，测量分布在不同气候环境中的六个实地地点的一套集水区，但在类似基岩中具有类似的起伏范围。 通过对不同地点的比较，这些数据将量化年平均降水量与侵蚀率之间的关系。对于塑造地球表面而言，没有什么问题比气候与侵蚀之间的关系更重要了。 因此，这里追求的研究问题有直接影响的问题，直接的社会相关性，包括气候对水库沉积率，自然灾害和土壤侵蚀率的影响。 气候在地表过程中的作用对于相关领域的基本问题同样重要。例如，人们对气候如何控制硅酸盐风化速率非常感兴趣，因为这一过程提取了大气中的二氧化碳，从而降低了温室气体的水平。侵蚀将影响硅酸盐风化的速率，因此将直接影响二氧化碳的去除。在控制沉积物流入盆地的过程中，气候与构造隆升的区别一直是地质科学中的一个难题。这项研究将为深入了解这一过程提供新的工具。