Collaborative Research: The Pulse of Holocene Glaciations in New Zealand's Southern Alps

合作研究：新西兰南阿尔卑斯山全新世冰川的脉动

• 批准号: 0823693
• 负责人: Robert Finkel
• 金额: $ 8.51万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0823693&HistoricalAwards=false
• 关键词: Collaborative; Research; Pulse; Holocene; Glaciations

Human civilizations have developed during the Holocene epoch that began approximately 11,500 years ago. The Holocene is classically considered a period of outstanding climate stability. However, recent paleoclimate records suggest that abrupt climatic shifts did occur within the Holocene and that some of those coincided with twists and turns in human history. Although directly influencing human habitat, temporal and spatial patterns, natural variability and driving mechanisms of Holocene climate are not well understood, hampering reliable evaluation of current climate change. Holocene climate swings were large enough to impact humans but small enough to get lost in the ?noise? of natural variability in most geological climate records. Glaciers in many areas on Earth, however, have responded sensitively and quickly to the Holocene climate changes and have produced distinctive landforms, or moraines. The age of these landforms directly indicates when these continental Holocene climate changes occurred, but so far a robust, uniform and reliable dating tool for moraines was lacking. Recent progress in the field of cosmogenic dating demonstrates that moraines can be dated with unprecedented accuracy throughout the Holocene period, allowing novel perspectives on the characteristics of Holocene climate changes. This grant is an interdisciplinary, multi-group effort to date the Holocene moraine sequences in New Zealand?s Southern Alps by applying high-precision 10Be surface exposure dating (SED) combined with local calibration of the 10Be production rate, to evaluate the underlying climate changes, and to analyze the results within an interhemispheric perspective. New Zealand appears to be an ideal location for such a study: (i) terrestrial paleoclimate data from southern mid-latitudes, influenced by tropical and polar signals, are sparse and urgently needed to evaluate the regional footprint of climate changes; (ii) up to five or more different Holocene moraines are preserved in front of individual glaciers, allowing insight into the details of the Holocene climate changes in southern mid-latitudes, including the ?Little Ice Age?; (iii) glaciers in southern mid-latitudes respond to atmospheric/oceanic changes (no continental climate effects); (iv) the general landform setting and rock type is well suited for our SED approach; (v) a suite of detailed glacier landform (geomorphologic) maps of New Zealand?s Southern Alps have been developed, paleo-snowlines have been reconstructed in detail, and glaciological modeling studies are ongoing by our collaborators, making this one of the better investigated glacier records on Earth. To achieve a regional, detailed chronology of glaciations on a prime site in southern mid-latitudes, we will combine large valley glacier systems with smaller valley glaciers on both, the semi-arid east flank as well as on the very humid west flank of the Southern Alps, evaluating the importance of different precipitation regimes for glaciations. We will compare our glacial chronologies to the few records available from New Zealand and elsewhere, testing the regional to inter-hemispheric character of the Holocene glacial pulse-beat. One of the foci herein will be the time period known as the ?Little Ice Age, where detailed historical records are available for European glaciers. Intellectual Merit and Broader Impacts: We expect to greatly improve our understanding of drivers of Holocene glacier fluctuations in southern mid-latitudes by tackling key questions such as: Were Holocene glaciations inter-hemispheric? Were atmospheric circulation changes involved in driving these events or were both, global and regional forces involved? This project represents a unique opportunity to create a reference data set of Holocene glacial fluctuations in southern mid-latitudes. These data should be of high value to calibrate climate models and to the broad community of climate scientists and glacial geologists. We further develop the method of cosmogenic 10Be dating and our geochemical/geochronological tool-kit will be applicable to future Holocene moraine-dating projects. The new atlas of geomorphic maps of the central Southern Alps will be updated with our glacial chronologies during this project. In addition to extending the LDEO/CU curriculum, a female master student will be educated, several early-career scientists will be involved, and high school students and teachers (?Lamont-Doherty Secondary School Field Program?) will actively participate in this project. Beyond standard data dissemination, we will present the project at public events, such as the annual L-DEO Open House (typically 4,000 visitors) and will use our close contacts to New York public media to seek coverage of this project in newspapers (New York Times) and television (History Channel). The project will foster the fruitful collaboration between the Lamont-Doherty Earth Observatory, the University of Maine, the UC Berkeley, and the GNS Science, NZ.

大约11500年前开始的全新世时期，人类文明已经发展。全新世在古典上被认为是杰出的气候稳定时期。但是，最近的古气候记录表明，全新世内确实发生了气候变化，其中一些与人类历史上的曲折相吻合。尽管直接影响人栖息地，时间和空间模式，但自然变异性和全新世气候的驾驶机制尚不清楚，从而阻碍了对当前气候变化的可靠评估。全新世的气候波动足够大，可以影响人类，但很小，足以在“噪音”中迷失吗？大多数地质气候记录中自然变异性。然而，地球许多地区的冰川对全新世气候变化的敏感和迅速反应，并产生了独特的地形或莫莱素。这些地形的年龄直接表明何时发生了这些大陆的气候变化，但是到目前为止，缺乏一种坚固，统一和可靠的约会工具。宇宙基因测量领域的最新进展表明，在整个全新世，可以以前所未有的准确性来确定冰ora，从而使人们对全新世气候变化的特征进行了新的观点。这笔赠款是迄今为止新西兰南部阿尔卑斯山全新世森林序列的跨学科，多组的努力，通过应用高级10BE表面曝光日期（SED）结合了10BE生产率的局部校准，以评估潜在的气候变化，并在互比的透视图中分析结果。新西兰似乎是这项研究的理想场所：（i）受到热带和极性信号影响的南部纬度的陆地古气候数据是稀疏而急需的，以评估气候变化的区域足迹； （ii）在单个冰川前保存了多达五个或更多不同的全新世羊角，可深入了解南部中期中期的全新世气候变化的细节，包括“小冰河时代？”； （iii）南部纬度南部的冰川对大气/海洋变化的反应（无大陆气候影响）； （iv）一般地形环境和岩石类型非常适合我们的SED方法； （v）开发了新西兰南部阿尔卑斯山的一套详细的冰川地面（地貌）地图，我们的合作者正在详细重建古猎人，并进行了冰科建模研究，使这是这是该地球上提到的冰川记录。为了在南部纬度地区的主要地点上实现冰川的区域性，详细的年代学，我们将在两者，半干旱的东侧面以及南部阿尔卑斯山的非常潮湿的西部侧面以及南部阿尔卑斯山的非常潮湿的西部侧面结合大型山谷冰川系统，并评估不同降水系统的重要性。我们将将我们的冰川时间顺序与新西兰和其他地方可用的少数记录进行比较，从而测试了全新世冰川脉冲孔的区域到半球间特征。本文中的一个焦点将是被称为“小冰河时代”的时期，欧洲冰川可以使用详细的历史记录。智力优点和更广泛的影响：我们希望通过解决以下关键问题（例如：全新世冰川症之间的关键问题？大气循环涉及驱动这些事件的变化还是全球和区域力量涉及？该项目是一个独特的机会，可以在南部纬度地区创建全新世冰川波动的参考数据集。这些数据对于校准气候模型以及气候科学家和冰川地质学家的广泛社区应该具有很高的价值。我们进一步开发了宇宙基因10be约会的方法，我们的年代/地质学工具套件将适用于未来的全新世森林约会项目。在此项目期间，我们的冰川年表将更新南部阿尔卑斯山中部的地貌图的新图集。除了扩展LDEO/CU课程外，还将接受一名女学生，还将参与一些早期职业科学家，高中生和老师（？Lamont-Doherty中学实地课程？）将积极参与该项目。除了标准数据传播之外，我们还将在公共活动中介绍该项目，例如年度L-DEO开放日（通常为4,000名游客），并将使用我们与纽约公共媒体的密切联系，以寻求在报纸（New York Times）和电视台（历史频道）中对该项目的报道。该项目将促进缅因州大学，加州大学伯克利分校和新西兰GNS Science的Lamont-Doherty Earth天文台之间的富有成果的合作。