Collaborative Research: Climatic Control of Erosion Rates and Landscape Morphology - Quantifying the Influence of Fluvial Thresholds

合作研究：侵蚀率和景观形态的气候控制 - 量化河流阈值的影响

• 批准号: 2229222
• 负责人: Kelin Whipple
• 金额: $ 40.15万
• 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: 2023
• 资助国家: 美国
• 起止时间: 2023-08-15 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2229222&HistoricalAwards=false
• 关键词: Collaborative; Research; Climatic; Control; Erosion

This project seeks to advance understanding of land surface response to climate change through study of evolving landforms on the Hawaiian islands. This research will improve scientists’ ability to decipher the record of past climates from landforms and to anticipate land surface response to future climate change. Planned research activities focus on the role of extreme events in canyon cutting – a topic that is central to landscape response to climate change but has received insufficient attention. The team will recruit two undergraduates from underrepresented communities in Hawaii to participate in the research effort and to attend an international professional conference to learn about opportunities and establish network connections. Outreach and hands-on public educational activities will be developed at both Arizona State University and the University of Indiana, including through participation of undergraduates in research efforts. All resulting research data will be made publicly available.This research will extend prior studies of the Hawaiian islands by examining landscapes across a span of islands, and thus landscape ages, and across the dramatic differences in rainfall between windward and leeward slopes, emphasizing the role of geomorphic thresholds and the extreme events that can exceed them. Preliminary investigation indicates that the kilometer-deep canyons common to all of the islands were cut rapidly to depths similar to the present day, after which incision stagnated because channel gradient decreased below a climate-dependent threshold for moving large boulders in channels. This study will systematically test the hypothesis that canyon cutting on the Hawaiian islands has been limited by boulder transport thresholds. A combination of methods will be deployed, including detailed field measurements, digital elevation model analyses, 40Ar/39Ar dating of inset lava flows, and estimates of catchment-mean erosion rates from cosmogenic 36Cl in magnetite in river sediment – a novel method only recently developed. This research represents an opportunity to advance understanding of climatic control on landscape evolution in general, and to quantify how fluvial incision thresholds critically modulate connections among climate, topography, and erosion rate. The Hawaiian islands provide unique conditions to directly measure fluvial thresholds and to quantitatively assess their role modulating climatic control of landscape evolution.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.

该项目旨在通过研究夏威夷群岛上不断发展的地貌来提高对气候变化的陆地表面反应的理解。这项研究将提高科学家的能力，使人们能够从地面上解密过去的气候记录，并预测对未来气候变化的土地表面反应。计划的研究活动集中于极端事件在峡谷切割中的作用，这是对气候变化的景观反应至关重要的话题，但没有得到足够的关注。该团队将招募来自夏威夷代表性不足的社区的两名本科生，以参加研究工作，并参加国际专业会议，以了解机会和建立网络联系。亚利桑那州立大学和印第安纳大学将开展外展和实践公共教育活动，包括通过大学生参与研究工作。所有结果的研究数据都将公开可用。这项研究将通过检查各个岛屿的景观，从而扩大夏威夷群岛的先前研究，从而扩展景观年龄，以及在迎风和背风懒之间的降雨差异上的巨大差异，从而强调了地球形阈值以及极端事件的作用，这些事件可能超过它们。初步研究表明，所有岛屿共有的公里深峡谷被迅速切成类似于当今的深度，此后切口停滞不前，因为通道梯度降低了以下，低于气候依赖性阈值，用于在通道中移动大巨石。这项研究将系统地检验以下假设：夏威夷群岛上的峡谷切割受到巨石运输阈值的限制。将部署方法的组合，包括详细的现场测量，数字高程模型分析，40AR/39AR的插图熔岩流量以及河流沉积物中磁铁矿中的流域均值侵蚀速率的估计 - 一种新的方法。这项研究代表了一个机会，可以提高对景观演化的气候控制的理解，并量化河流切口阈值如何严重调节气候，地形和侵蚀率之间的连接。夏威夷群岛提供了独特的条件，可以直接衡量河流阈值，并定量评估其对景观演化的民用控制的作用。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛影响的评估来评估的珍贵支持。