Ross Ice Shelf Geothermal Flux (RISGF) - Direct Borehole Measurements as Part of the New Zealand Ross Ice Shelf Programme

罗斯冰架地热通量 (RISGF) - 直接钻孔测量是新西兰罗斯冰架计划的一部分

• 批准号: 1745124
• 负责人: Slawek Tulaczyk
• 金额: $ 9.22万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1745124&HistoricalAwards=false
• 关键词: Ross; Ice; Shelf; Geothermal; Flux

The geothermal flux is a significant source of heat in polar subglacial environments. It affects the temperature at the base of ice sheets, influencing the distribution and rate of basal melting or freezing. These processes affect ice-sheet mass balance because basal melting facilitates fast sliding of ice. The geothermal flux is used in ice-sheet models that predict the contribution of the West Antarctic Ice Sheet to global sea-level rise. Yet, despite the importance of the geothermal flux, there are relatively few direct measurements, mainly because it is so difficult to access sub-ice environments. This project aims to obtain new constraints on the magnitude and spatial distribution of geothermal flux beneath the Ross Ice Shelf through collaboration with a New Zealand research project that is planning to drill through the ice shelf. Due to the paucity of observations, the geothermal flux distribution used in ice-sheet models typically falls within a relatively narrow range and is represented at low spatial resolution, based on geological or remotely-sensed properties of the underlying lithosphere. However, these models of Antarctic geothermal flux distribution do not appear to be consistent with each other in both magnitude and distribution, suggesting that spatial patterns of geothermal flux below the West Antarctic Ice Sheet are underconstrained. Using data collecting from a down-borehole geothermal probe, the team will test the hypothesis that the central part of the West Antarctic rift system is characterized by lower geothermal flux values than the previously sampled southern rift shoulder.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.

地热通量是极地冰下环境的重要热源。它影响冰盖底部的温度，影响底部融化或冻结的分布和速度。 这些过程会影响冰盖的质量平衡，因为底部的融化促进了冰的快速滑动。地热通量被用于冰盖模型，预测西南极冰盖对全球海平面上升的贡献。然而，尽管地热通量很重要，但直接测量相对较少，主要是因为很难进入冰下环境。该项目旨在通过与新西兰一个计划钻穿冰架的研究项目合作，获得罗斯冰架下地热通量的大小和空间分布的新限制。由于缺乏观测，冰盖模型中使用的地热通量分布通常福尔斯范围较窄，空间分辨率较低，其依据是底层岩石圈的地质或遥感特性。然而，这些模型的南极地热通量分布似乎并不相互一致的幅度和分布，这表明南极西部冰盖以下的地热通量的空间格局受到限制。利用从钻孔地热探测器收集的数据，该团队将测试这样的假设，即西南极裂谷系统的中部的地热通量值低于之前采样的南部裂谷肩。该奖项反映了NSF的法定使命，并且通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。