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

产生过去气候变化的机制在一定程度上可能是全球性的，但这种变化在气候系统和陆地环境中的表现因区域而异。鉴于最近的冰芯和海洋记录的结果，增加对这种时空变化的理解的必要性变得更加重要，这些结果为从最后一次全冰期到全新世过渡的复杂性提供了令人兴奋的新视角。要揭示陆地系统的时空变异性及其对气候变化的响应，需要从地球表面具有代表性的部分获得年代明确的地层记录。为此，这个研究项目涉及来自美国、法国和英国的地理学家和地球科学家，将为法国南部的卢瓦尔河、罗纳河和加龙河开发一个晚更新世和全新世景观演变的区域记录。长期项目目标是发展和完善这三个系统的地貌、地层学、沉积学和古水文模型，以分析它们在一个完整的冰期-间冰期旋回过程中是如何运作的。更具体地说，该项目将为“Wurm冰川旋回”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。它还将开发一个详细的地层学、沉积学和年代学框架，以千年尺度分辨率为三个河流系统在脱冰和向全新世过渡的非常活跃的时期。冰川-河流沉积物的年代学将通过使用光学刺激发光（OSL）和加速器质谱（AMS） 14C测年程序来开发。这些数据将用于评估这些河流系统在关键时期内变化的频率、幅度、差异敏感性和阈值。该研究项目将产生一个有价值的新数据库，并为一系列重要问题提供新的见解，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的个别河流系统和相对较小的区域收集的信息，并将为今后在区域范围内进行的研究提供参考标准。该项目由美国国家科学基金会地理与区域科学、地质与古生物学和西欧项目与法国国家科学研究中心（CNRS）共同支持。

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).