Pilot Project: Exploring the Paleoenvironmental Data Archived in Ice Deposits from Lava Tubes before Its Imminent Loss to Ice Melting

试点项目：在冰融化即将消失之前，探索熔岩管冰沉积物中存档的古环境数据

基本信息

批准号：
2024248
负责人：
Bogdan Onac
金额：
$ 18.13万
依托单位：
University of South Florida
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-01 至 2023-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2024248&HistoricalAwards=false
关键词：
Pilot Project Exploring Paleoenvironmental Data

项目摘要

This project uses funding for a two-year pilot study to explore the paleoclimate information potentially stored in ice cores recovered from a select number of lava tubes from El Malpais National Monument (ELMA) in western New Mexico, a region of great potential for drought research.Instrumental climate records indicate that drought patterns in southwestern North America are sensitive to Pacific Decadal Ocean (PDO) variability and to interactions between the El Niño Southern Oscillation (ENSO) and the North American Monsoon System (NAMS). A deeper understanding of the past (pre-instrumental) behavior of these modes could be helpful for improving predictions of future drought and pluvial cycles. Seasonally-accumulated ice in lava tubes may provide an high-resolution and well-dated record of changing climatic conditions that will test the overarching hypothesis that ENSO and NAMS variability were persistent features over the past millennia in the Southwest and that all major climate periods (e.g., Medieval Warm Period) were part of this pattern of decadal-to-interdecadal variability.This project aims to: 1) provide proof of concept for the use of stable isotopic composition of ice deposits in lava tubes where carbonates are not available for delta 18-Oxygen analyses; 2) contribute to a growing network of quantitative paleoclimate datasets that would add a critical spatial and temporal perspective to the understanding of aridity patterns in southwestern North America and associated synoptic climate teleconnections; and 3) develop high-resolution, decadal-to-interdecadal scale isotopic records from ice in lava tubes in the Southwest for the past 3,000 years. The project may also help address other important science questions such as: 1) How delta 18-Oxygen and deuterium excess of ice indicate changes in the moisture source and air temperature during ice formation? 2) How is hydroclimate variability in the south west U.S. reflected by the stable isotopic composition of ice and which of the large-scale modes of climate variability were operating over the past 3000 years? and 3) Can ice deposits be used to identify spatial patterns of aridity (megadroughts) in the Southwest during late Holocene. To address these questions, the ice isotopic record will be used in conjunction with radiocarbon dated charcoal recovered from ice and high-resolution tree-ring data available at ELMA.The potential Broader Impacts include support for a graduate student, the potential for developing a new archive of paleoclimate data, and the advancement of the science of drought in the southwestern U.S., an area of concern for current and future water resources.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.

该项目利用资金进行为期两年的试点研究，探索可能储存在冰芯中的古气候信息，这些冰芯是从新墨西哥州西部埃尔马尔佩斯国家纪念碑 (ELMA) 的选定数量的熔岩管中回收的，该地区在干旱研究方面具有巨大潜力仪器气候记录表明，北美西南部的干旱模式对太平洋年代际海洋（PDO）变化以及厄尔尼诺南方涛动（ENSO）与北美季风系统之间的相互作用敏感（NAMS）。对这些模式过去（仪器仪表出现之前）行为的更深入了解可能有助于改善对未来干旱和雨季循环的预测，可能会提供高分辨率和日期准确的记录。气候条件变化的研究将检验以下总体假设：ENSO 和 NAMS 变异性是西南地区过去几千年的持续特征，并且所有主要气候时期（例如中世纪温暖期）都是该项目旨在：1）为熔岩管中冰沉积物稳定同位素成分的使用提供概念证明，其中碳酸盐无法用于 Delta 18-氧分析2）；为不断增长的定量古气候数据集网络做出贡献，这将为了解北美西南部的干旱模式和相关的天气气候遥相关增加关键的空间和时间视角； 3) 开发西南地区熔岩管中冰过去 3000 年的高分辨率、年代际到年代际尺度的同位素记录该项目还可能有助于解决其他重要的科学问题，例如：1) δ18-氧和δ18-氧是如何形成的。冰中氘过量表明冰形成过程中水分源和空气温度的变化？ 2) 美国西南部的水文气候变化是如何通过稳定反映的？冰的同位素组成以及过去 3000 年中哪些大规模的气候变化模式正在发生？ 3) 能否利用冰沉积来确定全新世晚期西南地区干旱（特大干旱）的空间模式以解决这些问题。问题，冰同位素记录将与从冰中回收的放射性碳测年木炭以及 ELMA 提供的高分辨率树木年轮数据结合使用。潜在的更广泛影响包括支持研究生，开发新的古气候数据档案的潜力，以及美国西南部干旱科学的进步，这是当前和未来水资源关注的领域。该奖项反映了 NSF 的法定使命，并被视为值得通过使用基金会的智力优点和更广泛的影响审查标准进行评估来支持。