Collaborative Research: CMG --Quantifying Tectonic and Geomorphic Interpretations of Thermochronometer Data with Inverse Problem Theory

合作研究：CMG——用反问题理论量化测温仪数据的构造和地貌解释

• 批准号: 0724457
• 负责人: Kenneth Farley
• 金额: $ 18.91万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0724457&HistoricalAwards=false
• 关键词: Collaborative; Research; CMG; Quantifying; Tectonic

The grandeur of mountain topography has for millennia captured the attention of poets, artists, and scientists. How plate tectonic processes of mountain building and mountain erosion by surface processes interact to produce topography over millions of years is now at the forefront of Earth science research. A fundamental question that arises when studying the evolution of mountains is: what did the past topography of mountain ranges look like? This question has proven very difficult to answer. Recent developments in both computer modeling of mountain building and erosional processes, and developments in geochemistry have made progress in reconstructing paleotopography. Advances in new geochemical techniques and mathematics (inverse problem theory) now allow a means of testing computer model predictions with geochemical (thermochronometer) data from rocks exposed at the Earth's surface today. These data record the cooling history of rocks as they are exhumed to the surface by erosion and faulting. This interdisciplinary project is addressing questions and hypotheses that are fundamental to quantifying the evolution of mountain topography including: (1) How can geologically meaningful interpretations of tectonic and geomorphic processes influencing mountain topography be improved from an integration of thermochronometer data, computer modeling, and mathematics? (2) How sensitive are thermochronometer data to different mountain building and erosional processes and how can sampling strategies be optimized to improve interpretations? and (3) What is the magnitude and rate of topographic change that can be resolved from mathematical inversion of thermochronometer data? To address these questions, this project investigates the forward and inverse problems of mountain topographic evolution with a comprehensive model. Coupled 3D thermal, hydrologic, and kinematic computer models are under development in addition to a surface process model accounting for glacial, fluvial, and hillslope erosional processes. The coupled model is used to explore the sensitivity of thermochronometer data to different processes and mathematically invert a dense network of new and existing thermochronometer samples from the southern Coast Mountains, B.C., for the regional paleotopography. Field work is in progress for the collection of additional data. Several novel mathematical techniques are also under development. In particular, a low pass filter technique and a regularized iterative method are being used to solve the notoriously ill-posed backward parabolic equation and large scale, nonlinear inverse heat transport equation. These problems are by nature interdisciplinary and in the forefront of predicting and interpreting thermochronometer data and mountain topography.

山地形宏伟的宏伟人数千年来吸引了诗人，艺术家和科学家的注意。 现在，山地建筑和山区侵蚀的板块构造过程如何相互作用以在数百万年内产生地形，现在是地球科学研究的最前沿。研究山的演变时出现的一个基本问题是：过去的山脉范围的地形是什么样的？事实证明，这个问题很难回答。山区建筑和侵蚀过程的计算机建模以及地球化学发展方面的最新发展已在重建古角色摄影方面取得了进步。现在，新的地球化学技术和数学（反问题理论）的进步允许一种通过今天暴露在地球表面暴露的地球化学（热化学计）数据来测试计算机模型预测的方法。这些数据记录了岩石的冷却历史，因为它们被侵蚀和断层挖掘到表面。这个跨学科项目是解决量化山地形象发展至关重要的问题和假设，包括：（1）如何从热量表数据，计算机模型，计算机建模以及数学的整合中改善对构造和地貌过程的地质有意义的解释。 ？ （2）热化学计数据对不同的山区建筑和侵蚀过程的敏感性如何，如何优化采样策略以改善解释？ （3）从热力学计数据的数学反转可以解决的地形变化的幅度和速率是多少？ 为了解决这些问题，该项目通过综合模型调查了山地形演变的前进和反向问题。除表面过程模型外，还开发了耦合的3D热，水文和运动计算机模型，该模型占冰川，河流和山坡侵蚀过程。该耦合模型用于探索热量学计数据对不同过程的敏感性，并在数学上转化了来自卑诗省南部海岸山脉的新型和现有热力学仪样品的密集网络，以换成区域古谱。收集其他数据的现场工作正在进行中。几种新型的数学技术也正在开发中。特别是，一种低通滤波器技术和一种正则迭代方法被用于解决臭名昭著的不良后退抛物线方程和大规模的非线性逆热传输方程。 这些问题本质上是跨学科的，也是预测和解释热量学计数据和山地形态的最前沿。