Collaborative research: Is Anthropocene sedimentation in valley bottoms a geologically significant event?

合作研究：人类世谷底沉积是一个具有重大地质意义的事件吗？

• 批准号: 1451586
• 负责人: Dorothy Merritts
• 金额: $ 13.79万
• 依托单位: Franklin and Marshall College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1451586&HistoricalAwards=false
• 关键词: Collaborative; research; Anthropocene; sedimentation; valley

Non-technical description of the project's broader significance and importanceRecent research in geomorphology, the study of Earth's surface and the processes that shape it, has found that human modification of land in the northeastern U.S. over the past few centuries has resulted in large volumes of sediment being eroded from hillsides and deposited in valleys along rivers and streams. Prior research has suggested that this sediment transfer is the most important modification of Earth's landscape in tens of thousands of years. This project will evaluate the significance of these deposits on a regional scale by carefully measuring them in representative field locations and then using newly available high-resolution topographic data to extrapolate the findings to whole watersheds and regions. Knowledge of how human activities have contributed to landscape change is a prerequisite for informed land-management and restoration decisions. To ensure broad communication of project findings, the researchers will interact with policy makers, planners, government agencies, and non-profit organizations interested in stream and wetland conservation. This project also will include strong opportunities for student research, since the collaborating institutions are heavily invested in undergraduate education as a priority.Technical description of the project Recent global sedimentation studies demonstrate that rates of erosion due to human activities exceed the amount of sediment delivered to the oceans by rivers. At the same time, field-based studies at the channel to watershed scale have found large quantities of sediment stored in valley bottoms during the past few centuries. This project will bridge the gap between global and watershed-based approaches by quantifying the amount of Anthropocene (recent, human related) sediment stored in valley bottoms of the northeastern United States, and then comparing this amount to published volumes and timescales of (1) erosion from the landscape, and (2) deposition in reservoirs, lakes, and estuaries along the Atlantic margin. The research will use high-resolution topographic data to map the extent and thickness of this fill over large spatial areas (1,000-10,000 square km), and will test these methods using fieldwork (mapping, coring, geophysical data collection, sediment sampling and dating) in key watersheds. A central goal is to evaluate the extent to which sediment storage in the unglaciated mid-Atlantic region applies in the glaciated, less-studied New England region, where upland soils are thin, sediment sources are generally localized to glacial deposits, and large natural lakes and wetlands provide terrestrial accommodation space. The results of the project will help resolve the discrepancy between erosion and deposition rates at small spatial (watershed) and temporal (decadal to centennial) scales versus the rates that occur globally and over geological time.

对该项目在地貌学上更广泛的重要性和重要性研究的非技术描述，对地球表面的研究及其塑造的过程，发现过去几个世纪以来，美国东北部的土地修饰导致大量的沉积物从山坡上侵蚀，并在河流和河流沿河流中沉积。先前的研究表明，这种沉积物转移是数万年来对地球景观的最重要修改。该项目将通过在代表性的现场位置仔细测量它们，然后使用新近可用的高分辨率地形数据来将这些调查结果推断到整个分水岭和地区，从而评估这些沉积物在区域尺度上的重要性。了解人类活动如何促进景观变化是明智的土地管理和恢复决策的先决条件。为了确保项目调查结果进行广泛的沟通，研究人员将与对流和湿地保护感兴趣的政策制定者，计划人员，政府机构以及非营利组织进行互动。该项目还将包括有力的学生研究机会，因为作为优先事项，合作的机构大量投资于本科教育。对该项目的技术描述最近的全球沉积研究表明，由于人类活动所带来的侵蚀率超过了河流传递给海洋的沉积物的数量。同时，在过去几个世纪中，在流域量表的渠道基于现场的研究发现了大量存储在山谷底部的沉积物。 This project will bridge the gap between global and watershed-based approaches by quantifying the amount of Anthropocene (recent, human related) sediment stored in valley bottoms of the northeastern United States, and then comparing this amount to published volumes and timescales of (1) erosion from the landscape, and (2) deposition in reservoirs, lakes, and estuaries along the Atlantic margin.这项研究将使用高分辨率的地形数据来绘制大型空间区域（1,000-10,000平方公里）的填充的程度和厚度，并将在关键流域中使用现场工作（映射，芯，地球物理数据收集，沉积物采样和约会）测试这些方法。一个核心目标是评估无酸化的中大西洋地区的沉积物存储在多大程度上适用于冰川，研究较少的新英格兰地区，那里的山地土壤稀薄，通常将沉积物来源定位于冰川沉积物，大型天然湖泊和湿地提供地面可容纳空间。该项目的结果将有助于解决小空间（流域）和颞（art十年至百年）尺度的侵蚀和沉积速率之间的差异，而与全球和地质时间上发生的率相比。