Collaborative Research: GEMT: Bridging Multiple Time Scales of Erosion and Rock Uplift in Taiwan

合作研究：GEMT：弥合台湾侵蚀和岩石隆升的多个时间尺度

• 批准号: 2123412
• 负责人: Kaj Johnson
• 金额: $ 44.93万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2123412&HistoricalAwards=false
• 关键词: Collaborative; Research; GEMT; Bridging; Multiple

Mountains appear static to the casual observer, yet in many locations they are actively growing upward in response to plate tectonics, while their shape, height and width is altered by climate-driven erosion. How fast mountains change elevation depends on the timescale and locations in which one observes them. During an earthquake, mountains can move many meters in a matter of seconds, yet when earthquake motions are averaged over millions of years, and combined with the slow motion of faults that may happen between earthquakes, the rate that mountains move is much slower. How these slow, but continuous motions combine with short high-magnitude events to build topography of mountainous regions over millions of years is an important question to answer to understand how short-term, hazardous events like earthquakes, landslides, and floods integrate over long periods to build the spectacular scenery of mountain systems. In this proposed work, Taiwan is a natural, ongoing experiment of how uplift and erosion is integrated over a range of timescales to build the mountain range. The investigators will examine uplift and erosion over decadal, millennial, and million-year timescales to document changes in measured rates and build a framework for understanding discrepancies among the different approaches. The project will bring together US and Taiwanese scientists across career levels and disciplines to address this fundamental research question in tectonics. In year 2, U.S. and Taiwanese graduate students will come together for a month-long cross-disciplinary modeling workshop. Additionally, the project will support recruitment to STEM through an innovative course involving 1st year undergraduates who will be exploring geodetic and geomorphic data of Taiwan. This project is a collaborative effort between U.S. and Taiwanese researchers under the aegis of the NSF/GEO/EAR - MOST-Taiwan (GEMT) Collaborative Research opportunity.This project will build a new framework for bridging measurements of deformation rates across geodetic to geologic timescales, by building a suite of models that link deformational and erosional processes. The active Taiwan mountain belt is an excellent location to test hypotheses of how short-term processes such as the elastic earthquake cycle, river incision, and exhumation aggregate to build orogens and evolve topography. Taiwan is widely invoked as a case study for mountain belts in erosional or topographic steady-state, however, a number of observations challenge this classical view. Highly variable estimates of denudation and incision rates inferred over disparate time intervals raises questions about the time periods over which the concepts of steady-state mountain building are relevant in Taiwan. In addition, present-day uplift rates from geodesy are also not easily reconciled with the millennial and longer time-scale erosion rates. These confounding observations suggest that the mechanisms of mountain building broadly, and in Taiwan specifically, are not fully understood and fundamental questions remain unanswered about the relationship of deformation, tectonic uplift, and erosion over a wide range of time scales. We will build a series of kinematic models that simulate potential fault geometry and evolution and evaluate if the history of fault activity and geometric evolution is consistent with 0.5 Ma exhumation history constrained by thermochronology, geomorphically inferred millennial rates constrained by erosion and incision data, and present-day rock uplift rates constrained by geodesy. Our integrated approach will ensure that the model fault geometry and slip rates that dictate deformation kinematics, and their influence on the uplift field that drives river incision and exhumation, be compatible across time scales. To accomplish this integration, we propose a five-part research plan: (1) Build hundred-thousand to million-year kinematic orogenic models constrained by geology and thermochronology; (2) Build a millennial time-scale erosion model using river incision rate data, basin-wide CRN, and channel morphology; (3) Construct an updated geodetic vertical velocity field; (4) Construct earthquake cycle models of present day deformation; (5) Bridge time scales through model integration.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

山脉似乎对休闲观察者来说是静态的，但是在许多地方，它们在响应板块构造方面积极成长，而气候驱动的侵蚀会改变其形状，高度和宽度。山的变化速度的速度取决于人们观察到它们的时间表和位置。在地震期间，山脉可以在几秒钟内移动数米，但是当地震动作平均数百万年内，并且与地震之间可能发生的故障慢动作相结合时，山脉移动的速度的移动速度却慢得多。这些缓慢而连续的动作如何与短期的高磁性事件结合在一起，以建立数百万年的山区地形，这是一个重要的问题，可以回答以了解短期，危险事件（如地震，山体滑坡和洪水）如何在长期内整合到山系统的壮观风景中。在这项拟议的工作中，台湾是一项自然的，正在进行的实验，该实验是如何在各种时间范围内整合到山脉的时间范围内。调查人员将检查对年代，千禧年和百万年时间尺度的隆起和侵蚀，以记录测量率的变化，并建立一个框架，以了解不同方法之间的差异。该项目将跨职业和学科汇集我们和台湾科学家，以解决构造学中的这一基本研究问题。在第二年，美国和台湾研究生将聚在一起参加一个月的跨学科建模研讨会。此外，该项目将支持招聘，以涉及涉及第一年大学生的创新课程，他们将探索台湾的大地测量和地貌数据。该项目是美国和台湾研究人员在NSF/GEO/EAR的宙斯盾 - 大多数台湾（GEMT）协作研究机会之间的合作努力。该项目将建立一个新的框架，以通过建立一个链接地理时代的地理位置上的地理位置和ersos eros eRos repsitional Intigitional Intifientional pardositional Procesitionalcity Processity流程的框架来弥合地理位置上的变形率的测量框架。主动台湾山带是测试假设的绝佳位置，以说明诸如弹性地震周期，河流切口和挖掘骨料等短期过程以建立和进化地形。 台湾被广泛地作为侵蚀或地形稳态中山带的案例研究，但是，许多观察结果挑战了这种经典观点。通过不同时间间隔推断出的剥离和切口率的高度可变的估计提出了有关台湾稳态山区建筑概念在台湾相关的时间段的问题。此外，当今的大地升高率也不容易与千禧一代和更长的时间尺度侵蚀率核对。这些混淆的观察表明，尚未完全了解山区建设的机制，并且在台湾中尚未充分理解，并且基本问题仍然没有关于变形，构造隆起和侵蚀在广泛的时间范围内的关系。我们将构建一系列运动模型，以模拟潜在的故障几何形状和进化，并评估故障活动和几何进化的历史是否与受热量学约束的0.5 MA发掘历史相一致，地球损失和切口数据限制的千禧一代限制，以及当前的摇滚速率，以及当前的摇滚速率限制了地质的地质。我们的集成方法将确保模型故障几何形状和滑动速率决定变形运动学，以及它们对驱动河流切口和挖掘的隆起场的影响，在时间尺度上兼容。为了完成这一整合，我们提出了一个五部分的研究计划：（1）建立了受地质和热量学约束的数百万年度运动学模型； （2）使用河流切口率数据，盆地范围的CRN和渠道形态建立千禧一代的时间尺度侵蚀模型； （3）构建更新的大地垂直速度场； （4）构建当今变形的地震周期模型； （5）通过模型集成进行桥梁时间扩展。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的评论标准来评估值得支持的。