The Fluvial Response to Late Quaternary Climatic Change of Large Rivers in France

法国大河河流对晚第四纪气候变化的响应

• 批准号: 0414317
• 负责人: Michael Blum
• 金额: --
• 依托单位: Louisiana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-15 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0414317&HistoricalAwards=false
• 关键词: Fluvial; Response; Late; Quaternary; Climatic

The mechanisms that produced past climate changes may have been global in extent, but the manifestation of such changes in the climate system and on terrestrial environments varied regionally. The need for increased understanding of this spatial and temporal variability has become even more significant in light of the recent results from ice core and marine records, which provide exciting new glimpses of the complexity the transition from the last full-glacial to Holocene transition. Unraveling the spatial and temporal variability of terrestrial systems and their responses to climate changes requires clearly dated stratigraphic records from representative parts of Earth's surface. Toward that end, this research project involving geographers and Earth scientists from the U.S., France, and the United Kingdom will develop a region record of late Pleistocene and Holocene landscape evolution for the Loire, Rhone, and Garonne rivers of southern France. Long-term project goals are to develop and refine geomorphic, stratigraphic, sedimentologic, and paleohydrologic models for the three systems in order to analyze how they operated over the course of a complete glacial-interglacial cycle. More specifically, the project will develop a general stratigraphic, sedimentologic, and chronologic framework for these river systems during the "Wurm glacial cycle." It also will develop a detailed stratigraphic, sedimentologic, and chronologic framework at millennial-scale resolution for the three river systems during the very dynamic period of deglaciation and transition to the Holocene. The chronology of glacio-fluvial sediments will be developed through the use of optically stimulated luminescence (OSL) and accelerator mass spectrometry (AMS) 14C dating procedures,. These data will be used to evaluate the frequency, magnitude, differential sensitivities, and thresholds for change in these fluvial systems over that critical time period. This research project will generate a valuable new database and contribute new insights into a range of important issues, including (1) linkages between regional climate and hydrological systems and global atmosphere-cryosphere-ocean processes and (2) regional sensitivities to climate change. The database will complement information gathered from individual river systems elsewhere and from relatively small regions, and it will provide a reference standard for future studies conducted on a regional scale. The project is jointly supported by the Geography and Regional Science, Geology and Paleontology, and Western European programs at the National Science Foundation in collaboration with the French National Center for Scientific Research (CNRS).

造成过去气候变化的机制可能在一定程度上是全球性的，但这种变化在气候系统和陆地环境中的表现因地区而异。鉴于最近来自冰芯和海洋记录的结果，加强对这种时空变异性的了解的必要性变得更加重要，这些结果提供了令人兴奋的新的一瞥，使人们得以一窥从最后一次全冰期向全新世过渡的复杂性。要弄清陆地系统的空间和时间变异性及其对气候变化的反应，需要来自地球表面有代表性部分的明确年代的地层记录。为此，这项由来自美国、法国和英国的地理学家和地球科学家参与的研究项目将建立法国南部卢瓦尔河、罗纳河和加龙河晚更新世和全新世景观演变的区域记录。该项目的长期目标是开发和完善这三个系统的地貌、地层、沉积学和古水文模型，以分析它们在整个冰川-间冰期循环过程中的运作方式。更具体地说，该项目将为“Wurm冰川循环”期间的这些河流系统建立一个一般的地层学、沉积学和年代学框架。它还将在非常动态的冰川消融和向全新世过渡的时期为三个河流系统建立千年尺度的详细地层、沉积学和年代学框架。冰川沉积物的年代学将通过使用光学受激发光(OSL)和加速器质谱仪(AMS)14C测年程序来建立。这些数据将被用来评估这些河流系统在这一关键时间段内的频率、震级、区分敏感性和变化阈值。这一研究项目将产生一个有价值的新数据库，并对一系列重要问题提出新的见解，其中包括：(1)区域气候和水文系统与全球大气-冰冻圈-海洋过程之间的联系；(2)区域对气候变化的敏感性。该数据库将补充从其他地方和相对较小区域的个别河流系统收集的信息，并将为今后在区域范围内进行的研究提供参考标准。该项目由国家科学基金会的地理和区域科学、地质学和古生物学以及西欧项目与法国国家科学研究中心(CNRS)合作共同支持。