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

非技术描述：东南极洲拥有巨大的古老冰盖。隐藏在冰盖下的基岩可能会为今天的大陆是如何形成的提供线索，而冰本身则包含了远古时期地球大气的记录。现在有了新的钻探技术，可以从冰面下两公里以下的地方直接采样这些物质。然而，要想获得这些材料，就需要知道去哪里找。南极中部高原冰盖特征和演化(SPICECAP)项目将使用国际收集的航空测量数据，在南极附近的东南极寻找关键位置，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的位置。最终，科学家们感兴趣的是获取最古老的冰的样本，以解决有关冰河时代条件从4万到10万年周期变化的根本原因的问题。SPICECAP数据分析将为未来的钻探提供现场调查数据，并将增加对南极洲隐藏的冰和地质记录的整体了解。该项目涉及国际合作和利用国际收集的数据。SPICECAP项目将培训新的本科生、研究生和博士后水平的跨学科科学家。技术描述：这项研究的重点是处理和解释从南极冰盖南部高原国际收集的航空地球物理数据。这些数据包括探冰雷达数据、激光测高、重力和磁学。该项目将提供有关冰下地质趋势、冰/岩石界面的地形和特征以及冰的地层的信息。该项目还将为未来的钻探提供基准场地特征。未来的钻探地点和旧冰的深层冰芯要求将冰盖底部冻结到床上(即岩石和冰之间的界面没有游离水)，评估将绘制冻结和融化区域的范围。具体地说，预计该项目将取得三个主要成果。首先，这项研究将评估泰坦穹顶作为潜在的旧冰钻探前景的可行性。泰坦穹顶是位于南极附近的冰下高地地区。评估将包括通过处理和解释雷达数据来确定冰床的水力背景，通过绘制冰层中的冰川反射器并将其与最近南极的冰层地层学联系起来，来确定冰盖质量随时间的平衡，以及使用激光测高技术测量冰盖的几何形状。其次，这项研究将对泰坦穹顶地区的地质背景进行评估，以了解区域地质边界和基岩采样的潜力。对于这两个目标，我们将使用中国机会性收集的数据和最近的PolarGAP数据集。第三，该研究将对泰坦穹顶地区和穹顶C地区袭击地点目标的风险态势进行评估。这将使用团队之前在圆顶C收集的高分辨率数据集，该区域类似于在泰坦圆顶收集的较粗分辨率数据，并将使人们能够理解泰坦圆顶宽线间距所遗漏的东西。具体地说，我们将在有和没有高分辨率数据的情况下对冰下水文学进行建模，并从统计上检查冰下山脉(可能保存旧冰)和冰下湖泊(可能破坏旧冰)的探测情况，作为行距的函数。

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.