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.

小行星9725348 侵蚀卸载是造山过程中的一种重要力量;侵蚀速率和侵蚀方式影响着造山带的高度、岩性单元的露头形态，或许还影响着地壳变形的速率和方式。 分析构造和地表过程的相互作用需要定量地了解基岩河道系统的动力学。 也就是说，在构造活跃的河流景观中，基岩河道控制着侵蚀卸载的速率和模式，因为它们为实现地表剥蚀的山坡过程设定了下边界条件。 不幸的是，很少有人知道定量河流切割成基岩的过程中的许多方面，这限制了我们的能力，模拟基岩河道系统的演变。 特别是，需要现场数据来约束：（基岩切割率， （对构造力的瞬态响应模式， （信道响应时间尺度， （基岩河道宽度的控制，以及 （通道过程中过渡的形态学后果（例如，泥石流）。 在努力提高我们的能力，构造和表面过程之间的相互作用模型，我们建议检查基岩通道系统在三个现场：沿海排水的国王山脉的北方加州，冰后冲沟在手指湖地区的纽约，和刀溪在阿拉斯加的山谷一万烟。 我们选择这些地点是因为每个地点的气候和岩性在空间上是不变的，每个地点的隆起和气候历史相对受到很好的约束，每个地点都包含指示切割的地貌（例如，斯特拉特阶地）和构造扰动（例如，过度陡峭的河流段），提供了一种手段，评估切口率和模式的瞬态响应构造强迫。 我们将使用从这种比较分析中获得的数据，通过一系列的正演和反演模拟练习（2-D剖面和3-D景观演化模型），对基岩河道演化的现有数学模型进行定量约束。 结果将提供一个更完整的理解过程中的基岩渠道系统和改进的数学框架，分析景观演变和相互作用的构造，气候和地表过程。