Collaborative Research: Logistically Light Instrument Deployment for Estimation of Antarctic Basal Temperatures and Geothermal Heat Fluxes

合作研究：用于估算南极基础温度和地热热通量的后勤轻型仪器部署

• 批准号: 1543331
• 负责人: Scott Tyler
• 金额: $ 2.5万
• 依托单位: Board of Regents, NSHE, obo University of Nevada, Reno
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1543331&HistoricalAwards=false
• 关键词: Collaborative; Research; Logistically; Light; Instrument

Title: Logistically Light Instrument Deployment for Estimation of Antarctic Basal Temperatures and Geothermal Heat FluxesNon-Technical Description: New observations of Antarctic ice sheet variables are essential for drill-site selection for climate records, for understanding how ice dynamics affect sea level, and for investigating the geologic history of the continent. Temperature depth-profiles are of particular current interest for estimating basal temperature and geothermal heat flux in Antarctica. Antarctic geothermal heat flux is presently poorly known except at recent drilling sites, and is the largest unknown in determining basal conditions. However, current logistical costs greatly limit drilling to acquire temperature profiles. Our long-term goal is the development, testing and commissioning of a new means of acquiring englacial temperature profiles at much lower costs than existing methods. To that end, we will undertake laboratory experiments and numerical modeling to develop to a new way to use ice melt probes, rather than traditional drilling, to deploy temperature measurement equipment to depths of a kilometer and greater. To use melt probes for this purpose, we must keep the melted ice above such probes from freezing completely, so that cable can be fed continually down to the probe as it descends. This development will also open the way toward recovering melt probes, so as to prevent environmental impacts and expense of equipment left in the field. Our initial experiments and modeling will test the validity of our approach and make it ready for further testing in the field.Technical Description: We will undertake laboratory and modeling work (1) to reduce the technical risk in our approach to melt-probe deployment of Raman Distributed Temperature Sensing (DTS) cables; and (2) to begin development of a recoverable ice melt probe. Specifically, we will use numerical modeling of the Stefan problem with cylindrical symmetry to guide detailed designs for cable-heating and anti-freeze injection, and will test and revise candidate designs by means of laboratory testing. We will test the long-term stability of ethanol-filled melt holes, to gauge their suitability for recoverable melt probe systems for temperature measurement (where months-long thermal equilibration after installation will be required). We will gain experience with Raman DTS methods by employing DTS to measure critical temperature data in our laboratory experiments, both within the melt hole and in adjacent ice. To address recoverability, we will design and test a new melt head for the upper end of our ice melt probe, and demonstrate upward travel through a partially refrozen melt hole. Finally, we will publish both modeling and experimental results in peer-reviewed publications, and will present the project to a broad public audience in a special event at a Seattle museum of science and technology. The result of this work will be demonstrated technical readiness for testing in a subsequent project at larger ice-drilling test facilities at the earliest opportunity (prospectively, at the University of Wisconsin, following soon after completion of this project) and, following that, in the field.

标题：逻辑上轻的仪器部署，用于估算南极基础温度和地热磁通液技术描述：南极冰盖变量的新观察结果对于气候记录的钻井现场选择至关重要，以了解冰冰动力学如何影响海平面，以及研究陆面的地理历史。温度深度构造特别是目前估计南极洲基础温度和地热磁通量的目前感兴趣。南极地热通量目前是鲜为人知的，除了最近的钻探地点，并且是确定基础条件的最大未知数。但是，当前的后勤成本大大限制了钻井以获取温度概况。我们的长期目标是开发，测试和调试以比现有方法低得多的成本获取英语温度概况的新方法。为此，我们将进行实验室实验和数值建模，以开发一种使用冰熔体探针而不是传统钻孔的新方法，以将温度测量设备部署到一个公里和更大的深度。为了为此，我们必须将融化的冰固定在此类探针上方，以免完全冷冻，以便可以在下降时不断馈入探头。这一开发也将为恢复熔体探针的回收开辟道路，以防止环境影响和野外设备的费用。我们最初的实验和建模将测试我们方法的有效性，并准备好在现场进行进一步测试。技术描述：我们将进行实验室和建模工作（1），以减少我们融化拉曼分布温度传感（DTS）电缆融化方法的技术风险； （2）开始开发可回收的冰熔体探针。具体而言，我们将使用圆柱形对称性的Stefan问题的数值建模来指导详细的设计，以进行电缆加热和防冻剂注入，并通过实验室测试测试和修改候选设计。我们将测试充满乙醇的熔体孔的长期稳定性，以评估其适合回收熔体探针系统进行温度测量的能力（需要安装后数月的热量平衡）。我们将通过使用DTS在熔体孔和相邻冰中测量实验室实验中的临界温度数据来获得RAMAN DTS方法的经验。为了解决可恢复性，我们将设计和测试新的熔体头，以在冰融化探头的上端进行新的熔体，并展示了通过部分重新融化熔体的向上行驶。最后，我们将在同行评审的出版物中发表建模和实验结果，并将在西雅图科学技术博物馆的一次特别活动中向广泛的公众观众展示该项目。这项工作的结果将在随后在较大的冰钻测试设施的随后项目中进行测试的技术准备就绪，并以最早的机会（前瞻性地在威斯康星大学，在该项目完成后不久），然后在该领域中进行。