Collaborative Research: Southern Plateau Ice-sheet Characterization and Evolution of the Central Antarctic Plate (SPICECAP)

合作研究：南部高原冰盖特征和南极中部板块的演化（SPICECAP）

• 批准号: 1443690
• 负责人: Duncan Young
• 金额: $ 35.74万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1443690&HistoricalAwards=false
• 关键词: Collaborative; Research; Southern; Plateau; Ice

Non-technical description: East Antarctica holds a vast, ancient ice sheet. The bedrock hidden beneath this ice sheet may provide clues to how today's continents formed, while the ice itself contains records of Earth's atmosphere from distant eras. New drilling technologies are now available to allow for direct sampling of these materials from more than two kilometers below the ice surface. However, getting this material will require knowing where to look. The Southern Plateau Ice-sheet Characterization and Evolution of the Central Antarctic Plate (SPICECAP) project will use internationally collected airborne survey data to search East Antarctica near the South Pole for key locations that will provide insight into Antarctica's geology and for locating the oldest intact ice on Earth. Ultimately, scientists are interested in obtaining samples of the oldest ice to address fundamental questions about the causes of changes in the timing of ice-age conditions from 40,000 to 100,000 year cycles. SPICECAP data analysis will provide site survey data for future drilling and will increase the overall understanding of Antarctica's hidden ice and geologic records. The project involves international collaboration and leveraging of internationally collected data. The SPICECAP project will train new interdisciplinary scientists at the undergraduate, graduate, and postdoctoral levels.Technical description:This study focuses on processing and interpretation of internationally collected aerogeophysical data from the Southern Plateau of the East Antarctic Ice Sheet. The data include ice penetrating radar data, laser altimetry, gravity and magnetics.  The project will provide information on geological trends under the ice, the topography and character of the ice/rock interface, and the stratigraphy of the ice. The project will also provide baseline site characterization for future drilling. Future drilling sites and deep ice cores for old ice require that the base of the ice sheet be frozen to the bed (i.e. no free water at the interface between rock and ice) and the assessment will map the extent of frozen vs. thawed areas. Specifically, three main outcomes are anticipated for this project. First, the study will provide an assessment of the viability of Titan Dome, a subglacial highland region located near South Pole, as a potential old ice drilling prospect. The assessment will include determining the hydraulic context of the bed by processing and interpreting the radar data, ice sheet mass balance through time by mapping englacial reflectors in the ice and connecting them to ice stratigraphy in the recent South Pole, and ice sheet geometry using laser altimetry. Second, the study will provide an assessment of the geological context of the Titan Dome region with respect to understanding regional geologic boundaries and the potential for bedrock sampling. For these two goals, we will use data opportunistically collected by China, and the recent PolarGAP dataset. Third, the study will provide an assessment of the risk posture for RAID site targeting in the Titan Dome region, and the Dome C region. This will use a high-resolution dataset the team collected previously at Dome C, an area similar to the coarser resolution data collected at Titan Dome, and will enable an understanding of what is missed by the wide lines spacing at Titan Dome. Specifically, we will model subglacial hydrology with and without the high resolution data, and statistically examine the detection of subglacial mountains (which could preserve old ice) and subglacial lakes (which could destroy old ice), as a function of line spacing.

非技术性描述：东南极洲拥有一个巨大的，古老的冰盖。隐藏在冰盖下的基岩可能提供了今天大陆如何形成的线索，而冰本身包含了遥远时代地球大气的记录。现在有了新的钻探技术，可以从冰面以下两公里多的地方直接对这些物质进行取样。然而，要获得这些材料，需要知道在哪里寻找。南极板块南部高原冰盖特征和演变项目将利用国际上收集的航空勘测数据，在南极洲东部靠近南极的地方寻找关键地点，以便深入了解南极洲的地质情况，并确定地球上最古老的完整冰层的位置。 最终，科学家们有兴趣获得最古老的冰的样本，以解决有关冰河时代条件从40，000年到100，000年周期变化的原因的基本问题。 SPICECAP数据分析将为今后的钻探提供现场勘测数据，并将增进对南极洲隐藏冰和地质记录的全面了解。 该项目涉及国际合作和利用国际收集的数据。 SPICECAP项目将培养新的跨学科科学家在本科生，研究生和博士后水平。技术说明：这项研究的重点是处理和解释国际收集的航空地球物理数据从南极洲东部冰盖南部高原。 这些数据包括冰层穿透雷达数据、激光测高、重力和磁力数据，该项目将提供有关冰层下的地质趋势、冰/岩石界面的地形和特征以及冰层的地层学的资料。 该项目还将为今后的钻探提供基线场地特征。 未来的钻探地点和旧冰的深冰芯要求冰盖的底部被冻结到海床上（即岩石和冰之间的界面没有自由水），评估将绘制冻结与解冻区域的范围。具体而言，预计该项目将取得三项主要成果。 首先，这项研究将评估泰坦圆顶的可行性，泰坦圆顶是一个位于南极附近的冰下高地地区，作为一个潜在的古老的冰钻探前景。 评估将包括通过处理和解释雷达数据确定河床的水力环境，通过绘制冰中的冰内反射器并将其与最近南极的冰地层学联系起来来确定冰盖质量平衡，以及使用激光测高术确定冰盖几何形状。 第二，这项研究将评估泰坦穹丘区域的地质背景，以了解区域地质边界和基岩取样的可能性。 为了实现这两个目标，我们将使用中国随机收集的数据和最近的PolarGAP数据集。 第三，该研究将评估Titan Dome区域和Dome C区域RAID站点目标的风险状况。 这将使用团队之前在Dome C收集的高分辨率数据集，该区域类似于Titan Dome收集的粗分辨率数据，并将能够了解Titan Dome的宽线间距错过了什么。 具体来说，我们将在有和没有高分辨率数据的情况下对冰下水文进行建模，并统计检查冰下山脉（可以保存旧冰）和冰下湖泊（可以破坏旧冰）的检测，作为线间距的函数。

项目成果

ICECAP radargrams in support of the international old ice search at Dome C - 2016

支持 Dome C 国际旧冰搜索的 ICECAP 雷达图 - 2016

• DOI: 10.26179/5wkf-7361
• 发表时间: 2021
• 期刊: Australian Antarctic Data Centre
• 作者: YOUNG, DUNCAN;ROBERTS, JASON LEIGH;BLANKENSHIP, DONALD D;VAN OMMEN, TAS;RITZ, CATHERINE;CAVIITE, MARIE G.;FREZZOTTI, MASSIMO
• 通讯作者: FREZZOTTI, MASSIMO

Antarctic Bedmap data: Findable, Accessible, Interoperable, and Reusable (FAIR) sharing of 60 years of ice bed, surface, and thickness data

• DOI: 10.5194/essd-15-2695-2023
• 发表时间: 2023-07-17
• 期刊: EARTH SYSTEM SCIENCE DATA
• 影响因子: 11.4
• 作者: Fremand, Alice C.;Fretwell, Peter;Zirizzotti, Achille
• 通讯作者: Zirizzotti, Achille