Collaborative Research: P2C2--Evaluating Controls on Holocene Glacier Fluctuations and Climate Variability in the Southern Peruvian Andes

合作研究：P2C2——评估秘鲁南部安第斯山脉全新世冰川波动和气候变化的控制

• 批准号: 1103380
• 负责人: Joseph Licciardi
• 金额: $ 20.63万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1103380&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; Evaluating; Controls

Technical description of the projectThe main objectives of this project are to develop accurate and precise moraine ages in the Cordillera Vilcabamba of southern Peru, and to quantify the sensitivity of Holocene glaciers to climate changes, with the ultimate goal of elucidating Holocene climate variability and controls in the tropics. Initial work in the Vilcabamba has identified prominent glacial advances during the early Holocene and the 'Little Ice Age' interval, revealing a sequence of events that is broadly correlative with glacial records in Europe. These pilot results suggest climate teleconnections between the tropics and the North Atlantic region, but a more extensive array of data is needed to confidently identify regional glacial patterns and Holocene climate controls. This project will build substantially on initial findings by reconstructing glacial histories in additional valleys in the Vilcabamba using cosmogenic 10Be surface exposure dating of moraines, taking advantage of recent methodological advances that allow determination of extremely young (200 year) and precise isotopic ages. Supplementing 14C ages and paleoclimate proxy data will be obtained from sediment cores recovered from bogs situated between 10Be-dated moraines. Independent 14C age control for these moraines offers the potential to develop a new local calibration of the 10Be production rate. The sensitivity of paleo-glacier mass balances to prescribed changes in specific climatic variables will be quantified by performing simulations with a glacier surface energy-mass balance model, thus allowing an estimation of the relative roles of major forcings such as temperature, precipitation, and solar radiation on glacier extent. Posited mechanisms of climate change will be assessed for their degree of consistency with the integrated age control and modeling results, enabling identification of likely drivers of Holocene glaciations and climate variability in the tropical Andes.Broader significance and importanceThe role of the tropics in triggering, amplifying, and transmitting global climate signals remains a topic of vigorous debate in climate science. Accurately dated records of past fluctuations in climatically sensitive tropical mountain glaciers are among the best indicators of regional trends in past climate changes and their causes. Peru harbors 71% of the world?s present-day tropical glaciers, and contains abundant geologic evidence of former glacier expansions. However, chronologies of past glacier fluctuations in this region are scarce, particularly during the Holocene epoch (the past ~11,700 years). New results from this project will contribute significantly toward an understanding of both the timing of Holocene glacier events in Peru and the predominant climatic influences on glaciation. Importantly, the new glacier chronologies will augment records of past climates developed from nearby ice core, lake, and marine sites as well as other emerging glacial histories, contributing to a more comprehensive characterization of regional climate changes and their environmental consequences. Results will thus allow for a rigorous examination of the underlying causes of tropical climate variability during the Holocene, including recent climate shifts relevant to understanding modern and future climate change.An improved understanding of past Andean glaciations is crucial for predicting glacier responses to future climate change and consequences for local water resources, and for identifying environmental impacts on ancient civilizations in the region, including Inca and pre-Inca societies. This study will provide training in field techniques, laboratory methods, and numerical modeling for undergraduate and graduate students at the University of New Hampshire and Columbia University. The project will also expand on a productive collaboration between early career U.S. scientists and collaborators in Canada and Peru. Assembly of this multinational project team will enhance the development of research programs, facilities, and outreach activities at each participating institution. Research activities will also contribute to technique development by refining laboratory methods aimed at increasing the precision of widely used isotopic dating methods.

项目的技术描述该项目的主要目标是在秘鲁南部的Cordillera Vilcabamba中建立准确，精确的冰ora年龄，并量化全新世冰川对气候变化的敏感性，这是阐明热带地区全新世气候变化和控制的最终目标。 Vilcabamba的最初工作已经确定了全新世早期和“小冰河时代”间隔的显着冰川进步，揭示了一系列事件，这些事件与欧洲的冰川记录大致相关。这些试点结果表明，热带地区和北大西洋地区之间的气候链接连接，但是需要更广泛的数据来自信地识别区域冰川模式和全新世气候控制。该项目将通过最初的山谷中的其他山谷中的冰川元素10BE表面暴露年代的约会来基于初始发现，从而利用了最近的方法论上的进步，从而确定了极年轻（200年）和精确的同位素年龄。补充14C年龄和古气候代理数据将从从位于10个日期的Moraines之间的沼泽中回收的沉积物核心获得。这些Moraines的独立14C年龄控制具有开发10BE生产率的新局部校准的潜力。古冰川质量平衡对特定气候变量的规定变化的敏感性将通过使用冰川表面能量质量平衡模型进行模拟来量化，从而可以估算主要强度的相对作用，例如温度，降水量，降水量和太阳辐射在冰川范围内的估计。将评估气候变化的提出机制，以评估其与年龄控制和建模结果的一致性的程度，从而鉴定了热带安第斯山脉中的全新世冰川的可能驱动因素和气候变化。热带的重要性和进出口的重要性在触发，扩增，传播势力竞争的情况下，这些热带的作用在触发，扩增和传播的是有力的竞争中。在气候敏感的热带山地冰川中，过去波动的准确记录是过去气候变化及其原因的区域趋势的最佳指标。秘鲁拥有当今世界上有71％的热带冰川，并包含了以前冰川扩张的大量地质证据。但是，该地区过去冰川波动的时间顺序很少，尤其是在全新世时期（过去〜11,700年）。该项目的新结果将有助于了解秘鲁全新世冰川事件的时机和主要气候对冰川的影响。重要的是，新的冰川年代将增加从附近的冰核，湖泊和海洋场所以及其他新兴的冰川历史发展的过去气候的记录，从而有助于更全面地表征区域气候变化及其环境后果。因此，结果将允许对全新世期间热带气候变异性的根本原因进行严格的检查，包括最近与理解现代和未来的气候变化有关的气候变化。对过去的安第斯山脉冰川的改善理解对于预测对未来气候变化的冰川反应至关重要，对未来的气候变化以及对环境的影响以及对环境的影响，包括对古老的环境和范围的影响。这项研究将为新罕布什尔大学和哥伦比亚大学的本科和研究生提供现场技术，实验室方法和数值建模的培训。该项目还将扩展加拿大和秘鲁的早期职业科学家与合作者之间的富有成效的合作。这个跨国项目团队的集会将增强每个参与机构的研究计划，设施和外展活动的开发。研究活动还将通过提高旨在提高广泛使用的同位素约会方法精确度的实验室方法来为技术开发做出贡献。