EAGER: Exploration of the Denali Basal Ice Core Archive

该奖项在早期探险研究概念基金(EIGHER)项目的支持下，利用资金来探索利用山上的基冰。亨特(德纳利国家公园)冰芯，用于重建阿拉斯加中部全新世的水文气候变化。在这个迫切的项目中采用的方法将测试在核心底部10米处的测年限制的可行性，并探索新的古气候代理测量方法。研究人员的目标是解决以下问题：1)在山基冰中是否存在整合地层。研究人员将探索使用新的高分辨率(激光烧蚀电感耦合等离子体质谱，微稳定同位素分析)和14碳测量来检验地层连续性假说的可行性。如果测量技术提供了具有适当误差的年代学信息，并且德纳利冰芯档案证明具有连续的地层记录，那么全新世的很大一部分可能会被记录在档案中。2)阿拉斯加中部整个全新世夏季温度的历史是什么？研究人员将测试一种新的方法，利用扫描电子显微镜(SEM)来分析压缩融化特征，这有可能显著扩展我们对过去夏季温度变化的了解。3)冰层在山上存在了多久。猎人高原？获取山体最低部分的底质的途径。猎人冰芯为在阿拉斯加中部研究这一问题提供了机会。研究人员将对岩心底部包含的小鹅卵石和沉积物进行宇宙成因同位素分析(10-Berillium)的有效性测试。这种分析在高山冰芯中回收的致岩物质上是独一无二的。如果成功，对基冰样品的宇宙成因同位素分析将为冰川学、古气候、冰川地质学和冰下环境学科的结合开辟新的研究途径。对德纳利冰芯档案中新测量数据的探索可能会在几个重要的古气候前沿提供科学突破，例如：1)改善和延长现有冰芯积累时间序列，并评估全新世期间的水气候可变性；2)评估各种气候可变性模式，特别是厄尔尼诺-南方涛动(ENSO)对全新世北太平洋区域气候的影响；3)了解水文循环的区域差异，特别是考虑到与ENSO有关的可变性对北太平洋水文学的潜在社会影响；4)评估记录的暖期期间的区域水文气候可变性和冰川反应(全新世气候最佳)；5)宇宙成因同位素分析的勘察工作可能会产生关于阿拉斯加中部冰在更长时间段内稳定性的有价值的初步信息。这是朝着设计和实施一项全面的研究战略迈出的重要一步，该战略涉及阿拉斯加的长期(例如，上更新世)冰川动力学。这样的结果将对整个地球科学产生广泛的影响。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award uses funds, under the auspices of the EArly Concept Grant For Exploratory Research (EAGER) program, to explore the use of the basal ice from the Mt. Hunter (Denali National Park) ice core for reconstructing hydroclimate variability in Central Alaska through the Holocene. The approach employed in this EAGER project will test the viability of dating constraints in the bottom ten meters of the core and explore new approaches for paleoclimate proxy measurement. The researchers aim to address the following questions:1) Are there conformable strata within the basal ice of Mt. Hunter?The researchers will explore the feasibility of using novel high resolution (laser ablation ICP-MS, micro-stable isotope analyses) and 14-Carbon measurements to test the stratigraphic continuity hypothesis. If the measurement techniques provide chronological information with appropriate errors and the Denali ice core archive proves to have a continuous stratigraphic record, then a large portion of the Holocene may be accessible in the archive.2) What is the history of summer temperature in Central Alaska through the Holocene?The researchers will test a new approach to analyze compressed melt features using Scanning Electron Microscopy (SEM) that has the potential to significantly expand our knowledge of past summer temperature variability.3) How long has ice been present on the Mt. Hunter plateau?Access to bed material contained in the lowest portion of the Mt. Hunter ice cores provides an opportunity for investigation of this question in Central Alaska. The researchers will test the validity of cosmogenic isotope analysis (10-Berillium) on small pebbles and sediment contained in the basal core sections. Such analyses are unique on lithogenic material recovered in an alpine ice core.If successful, cosmogenic isotope analysis of samples from basal ice will open new research avenues for combining glaciological, paleoclimate, glacial geology, and subglacial environment disciplines. Exploration of new measurements in the Denali ice core archive will potentially provide scientific breakthroughs on several important paleoclimate fronts such as: 1) improvement and extension of existing ice core accumulation time series, and evaluation of hydroclimate variability over the Holocene; 2) evaluation of the impact of various modes of climate variability, particularly El Nino-Southern Oscillation (ENSO), on regional climate in the North Pacific over the Holocene; 3) understanding regional differences in the hydrological cycle particularly given the potential societal impacts of ENSO-related variability on North Pacific hydrology; 4) evaluation of regional hydroclimate variability and glacier response during a documented warm period (Holocene climate optimum); and 5) reconnaissance effort with cosmogenic isotope analyses may yield valuable initial information on ice stability in Central Alaska over much longer time periods. This as an important step towards designing and implementing a comprehensive research strategy addressing long-term (e.g., Plio-Pleistocene) ice dynamics in Alaska. Such results would have a broad impact across the geosciences.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.