Collaborative research: acoustic logging of the WAIS Divide borehole

合作研究：WAIS Divide 钻孔的声波测井

• 批准号: 0944285
• 负责人: Sridhar Anandakrishnan
• 金额: $ 16.45万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0944285&HistoricalAwards=false
• 关键词: Collaborative; research; acoustic; logging; WAIS

0944199/MatsuokaThis award supports a project to test the hypothesis that abrupt changes in fabric exist and are associated with both climate transitions and volcanic eruptions. It requires depth-continuous measurements of the fabric. By lowering a new logging tool into the WAIS Divide borehole after the completion of the core drilling, this project will measure acoustic-wave speeds as a function of depth and interpret it in terms of ice fabrics. This interpretation will be guided by ice-core-measured fabrics at sparse depths. This project will apply established analytical techniques for the ice-sheet logging and estimate depth profiles of both compressional- and shear-wave speeds at short intervals (~ 1 m). Previous logging projects measured only compressional-wave speeds averaged over typically 5-7 m intervals. Thus the new logger will enable more precise fabric interpretations. Fabric measurements using thin sections have revealed distinct fabric patterns separated by less than several meters; fabric measurements over a shorter period are crucial. At the WAIS Divide borehole, six two-way logging runs will be made with different observational parameters so that multiple wave-propagation modes will be identified, yielding estimates of both compressional- and shear-wave speeds. Each run takes approximately 24 hours to complete; we propose to occupy the boreholes in total eight days. The logging at WAIS Divide is temporarily planned in December 2011, but the timing is not critical. This project?s scope is limited to the completion of the logging and fabric interpretations. Results will be immediately shared with other WAIS Divide researchers. Direct benefits of this data sharing include guiding further thin-section analysis of the fabric, deriving a precise thinning function that retrieves more accurate accumulation history and depth-age scales. The PIs of this project have conducted radar and seismic surveys in this area and this project will provide a ground truth for these regional remote-sensing assessments of the ice interior. In turn, these remote sensing means can extend the results from the borehole to larger parts of the central West Antarctica. This project supports education for two graduate students for geophysics, glaciology, paleoclimate, and polar logistics. The instrument that will be acquired in this project can be used at other boreholes for ice-fabric characterizations and for englacial hydrology (wetness of temperate ice).

0944199/Matsuokathis奖支持一个项目，以检验以下假设：织物突然存在，并且与气候过渡和火山喷发都相关。它需要对织物的深度连续测量。通过在核心钻井完成后将新的记录工具降低到WAIS分隔井中，该项目将测量声波速度作为深度的函数，并用冰面料来解释它。这种解释将以稀疏深度的冰核测量织物为指导。 该项目将在冰片记录日志记录和估算压缩波和剪切波速度的深度概况（〜1 m）中应用既定的分析技术。以前的记录项目仅测量了通常在通常5-7 m间隔的压缩波速度。因此，新的记录仪将实现更精确的织物解释。使用薄部分的织物测量结果显示出不同的织物图案不到几米。较短时间内的织物测量至关重要。 在WAIS Divide钻孔上，将使用不同的观察参数进行六次双向记录运行，以便将确定多个波浪传播模式，从而对压缩波和剪切波速度进行估计。每次跑步大约需要24小时才能完成；我们建议在总共八天内占据钻孔。 WAIS Divide的登录时间是在2011年12月暂时计划的，但时机并不重要。 该项目的范围仅限于完成日志和织物解释的完成。 结果将立即与其他WAIS分裂研究人员共享。该数据共享的直接好处包括指导对织物的进一步薄片分析，得出精确的稀疏功能，可以检索更准确的积累历史记录和深度年龄尺度。该项目的PI在该领域进行了雷达和地震调查，该项目将为这些区域遥感评估的冰内部提供基础真理。反过来，这些遥感手段可以将结果从井眼扩展到中西部南极的大部分。 该项目为两名研究生的地球物理学，冰川学，古气候和极地物流提供教育。该项目将获得的仪器可以在其他钻孔中用于冰塑料表征和Englacial水文（温带冰的湿度）。