RUI: COLLABORATIVE RESEARCH: Dynamic Response of Bedrock Fluvial Systems to Tectonic Forcing

RUI：合作研究：基岩河流系统对构造强迫的动态响应

• 批准号: 9725348
• 负责人: Dorothy Merritts
• 金额: $ 7.73万
• 依托单位: Franklin and Marshall College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-01-01 至 2001-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9725348&HistoricalAwards=false
• 关键词: RUI; COLLABORATIVE; RESEARCH; Dynamic; Response

9725348 Merritts Erosional unloading is an important force in orogenic processes; the rates and patterns of erosion influence the heights of mountain belts, outcrop patterns of lithologic units, and, perhaps, the rates and styles of crustal deformation. Analysis of the interactions of tectonic and surficial processes requires quantitative understanding of the dynamics of bedrock channel systems. That is, in tectonically active fluvial landscapes bedrock channels control the rates and patterns of erosional unloading because they set the lower boundary condition for hillslope processes that accomplish land surface denudation. Unfortunately, little is known quantitatively about many aspects of the process of river incision into bedrock, and this limits our ability to model the evolution of bedrock channel systems. In particular, field data are needed to constrain: ( rates of bedrock incision, ( Patterns of transient response to tectonic forcing, ( Channel response timescales, ( Controls on bedrock channel width, and ( Morphological consequences of transitions in channel processes (e.g., fluvial to debris flow). In an effort to improve our capabilities to model interactions between tectonic and surface processes, we propose to examine bedrock channel systems at three field sites: coastal drainage's of the King Range of northern California, post-glacial gullies in the Finger Lakes region of New York, and Knife Creek in the Valley of Ten Thousand Smokes in Alaska. We chose these sites because climate and lithology are spatially invariant in each, uplift and climatic histories of each are relatively well-constrained, and each contains landforms indicative of incision (e.g., strath terraces) and tectonic disturbance (e.g., oversteepened stream segments) that provide a means of assessing incision rates and patterns of transient response to tectonic forcing. We will use data obtained from this comparative analysis to place quantitative constraints on an existing mathematical mod el of bedrock channel evolution through a series of forward and inverse modeling exercises (both 2-D profile and 3-D landscape evolution models). The results will provide a more complete understanding of processes in bedrock channel systems and an improved mathematical framework for the analysis of landscape evolution and the interaction of tectonic, climatic and surficial processes.

9725348 Merritts侵蚀性卸载是造山过程中的重要力量。侵蚀的速率和模式会影响山带的高度，岩性单元的露头模式，以及也许是地壳变形的速率和样式。 分析构造和表面过程的相互作用需要定量了解基岩通道系统的动力学。 也就是说，在构造活跃的河流景观中，基岩通道控制着侵蚀卸载的速率和模式，因为它们为完成陆地表面剥离的山坡过程设定了下边界条件。 不幸的是，关于河流切口到基岩的许多方面的许多方面，几乎没有众所周知，这限制了我们建模基岩通道系统演变的能力。 特别是，需要进行现场数据来约束：（基岩切口的速率（对构造强迫的瞬时响应模式（通道响应时间尺度（基于基岩通道宽度的控制）（过渡宽度和通道过程中的形态学后果）（例如，在频道过程中，对debris流动的河流对融合的互动和表面的互动）的三个努力和表面的交互作用。地点：北加州国王山脉的沿海排水，纽约的手指湖区的冰川沟渠以及阿拉斯加一万个烟雾的刀溪，我们选择了这些地点，因为气候和岩性在每种情况下都是在每个处于空间上的不变的，并且每个人都有良好的范围（均具有良好的范围）。梯田）和构造干扰（例如，渗透式流段），提供了一种评估切口率和对构造强迫的瞬时响应模式的方法。 我们将使用从此比较分析获得的数据通过一系列的正向建模练习（2-D轮廓和3-D景观演化模型），将定量约束放在基岩通道演化的现有数学模型中。 结果将为基础通道系统中的过程提供更完整的了解，并改进了景观演化分析以及构造，气候和表面过程的相互作用的数学框架。