Collaborative Research: Timing and structure of the last glacial maximum and termination in southern Peru: Implications for the role of the tropics in climate change

合作研究：秘鲁南部末次盛冰期和终止的时间和结构：热带地区在气候变化中的作用的影响

• 批准号: 1003471
• 负责人: Brenda Hall
• 金额: $ 21.7万
• 依托单位: University of Maine
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2014-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1003471&HistoricalAwards=false
• 关键词: Collaborative; Research; Timing; structure; last

The role of the tropics in climate change has important implications for understanding both orbital-scale and abrupt climate variations. Yet our ability to assess tropical behavior during major climate events, such as the last glacial maximum (LGM), is limited by poor spatial coverage and insufficient control on sample ages. This project will address this problem by developing well-dated records of glacial fluctuations from the LGM through the termination and late-glacial period at Nevados Coropuna and Allinccapac in southern Peru and use these data in numerical simulations of glacier mass balance and local climate. These sites allow an examination of glacier variations, as well as coeval snowline changes, along a transect from the arid (Coropuna) to the humid (Allinccapac) Andes and thus document how major climate events may have been expressed in areas with distinctly different environments. This work consists of detailed mapping of moraines; precise surface-exposure age dating (3He and 10Be) of carefully selected boulders from moraine crests and drift edges; basal 14C ages of bogs interspersed among moraines; calculation of former snowline depression; and modeling of the relationship between glacier mass-balance changes and climate. The work will be an important step towards understanding tropical behavior and will finally allow a thorough testing of the Milankovitch hypothesis of ice ages in the tropics.Broader Impacts: This research educates and trains students, a postdoc, and a recent female Ph.D. There is a lecture series on local geology and global climate change given to eco-tourism students at the University of Arequipa, as well as lectures to the Lima archaeology department. K-12 students benefit through a long-standing associations with classrooms in rural, commonly economically disadvantaged Maine. The project maintains a website and is exploring a learning module. In addition, the research is part of a joint initiative to understand land use and settlement patterns of the first Americans in the Peruvian highlands.

热带地区在气候变化中的作用对于理解轨道尺度和气候突变具有重要意义。然而，我们评估重大气候事件（例如末次盛冰期（LGM））期间热带行为的能力受到空间覆盖范围差和对样本年龄控制不足的限制。该项目将通过开发秘鲁南部 Nevados Coropuna 和 Allinccapac 的末次盛冰期到冰期终止和晚冰期期间的冰川波动的详细记录来解决这个问题，并将这些数据用于冰川质量平衡和当地气候的数值模拟。这些地点可以沿着从干旱（Coropuna）到潮湿（Allinccapac）安第斯山脉的横断面检查冰川变化以及同期雪线变化，从而记录主要气候事件如何在环境截然不同的地区表现出来。这项工作包括详细绘制冰碛；对从冰碛顶部和漂移边缘精心挑选的巨石进行精确的表面暴露年龄测定（3He 和 10Be）；散布在冰碛之间的沼泽的基础 14C 年龄；计算前雪线洼地；冰川质量平衡变化与气候之间关系的建模。这项工作将是了解热带行为的重要一步，并将最终对热带冰河时代的米兰科维奇假说进行彻底检验。 更广泛的影响：这项研究教育和培训了学生、博士后和最近的女博士。为阿雷基帕大学生态旅游专业的学生举办了关于当地地质学和全球气候变化的系列讲座，并为利马考古系举办了讲座。 K-12 学生通过与缅因州农村地区、经济上普遍处于不利地位的教室的长期合作关系而受益。该项目维护一个网站并正在探索一个学习模块。此外，该研究是了解秘鲁高地第一批美国人的土地利用和定居模式联合倡议的一部分。