Collaborative Research - Transantarctic Mountains Deformation Network: GPS Measurements of Neotectonic Motion in the Antarctic Interior

该奖项由极地项目办公室的南极地质和地球物理项目提供，支持在扩展的跨南极山脉变形网络（TAMDEF）中对基岩地壳运动进行GPS测量的项目，以记录由于南极西部裂谷的构造变形和/或南极冰盖的质量变化而引起的新构造位移。与活跃的新构造裂谷、走滑平移和火山活动相关的水平位移将通过监测横跨南极山脉和罗斯海近海岛屿的基岩GPS站的TAMDEF和意大利VLNDEF联合网络得到严格限制。由于末次盛冰期以来的消冰作用和现代冰原质量变化引起的冰川均衡调整将根据gps导出的地壳运动以及来自其他项目的关于冰原结构、厚度、消冰历史和现代质量平衡的新信息进行模拟。在维多利亚地地区正在进行的构造和地震调查的构造和流变信息也将被整合到建模中。综合和迭代建模将产生新构造和冰盖历史的整体解释，这将有助于我们区分构造地壳位移和粘弹性/弹性冰川均衡运动。这些结果将为解释稀疏的、区域分布的GPS连续跟踪器和星载仪器探测到的广泛的、大陆尺度的地壳运动模式提供关键信息。这项研究将有助于关注南极新构造和全球变化问题的国际项目。实现这些科学目标的策略包括对现有TAMDEF网络中的关键站点进行重复调查，沿着南极横贯山脉向南扩展TAMDEF站点阵列约250公里，将测量与VLNDEF网络联系起来，并在运动网络中集成准连续跟踪器。通过向南扩展基岩位置阵列，这些测量结果将跨越预测垂直运动的梯度，这是由于粘弹性反弹。向南延伸还可以确定活跃的恐怖裂谷的南部边界，并将为整个南极西部裂谷系统的任何正在进行的构造位移的约束提供更好的基线，这可能使用南极西部GPS网络收集的GPS数据。该项目还将调查南极洲GPS大地测量的独特方面，以确定误差谱与中纬度地区的比较，并确定适合南极条件的最佳测量和数据处理方案。大地测量学研究将提高我们网络中的定位精度，也将为极地地区的变形监测网络提供一般建议。计划开展一项教育和推广计划，目标是在俄亥俄州立大学学习地球系统科学的非科学专业本科生。目的是为非科学家阐明研究过程。这项努力将教育学生了解科学的过程，并使他们了解南极洲及其与全球科学问题的关系。

OPP-0230285/OPP-0230356PIs: Wilson, Terry J./Hothem, Larry D.This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to conduct GPS measurements of bedrock crustal motions in an extended Transantarctic Mountains Deformation network (TAMDEF) to document neotectonic displacements due to tectonic deformation within the West Antarctic rift and/or to mass change of the Antarctic ice sheets. Horizontal displacements related to active neotectonic rifting, strike-slip translations, and volcanism will be tightly constrained by monitoring the combined TAMDEF and Italian VLNDEF networks of bedrock GPS stations along the Transantarctic Mountains and on offshore islands in the Ross Sea. Glacio-isostatic adjustments due to deglaciation since the Last Glacial Maximum and to modern mass change of the ice sheets will be modeled from GPS-derived crustal motions together with new information from other programs on the configurations, thicknesses, deglaciation history and modern mass balance of the ice sheets. Tectonic and rheological information from ongoing structural and seismic investigations in the Victoria Land region will also be integrated in the modeling. The integrative and iterative modeling will yield a holistic interpretation of neotectonics and ice sheet history that will help us to discriminate tectonic crustal displacements from viscoelastic/elastic glacio-isostatic motions. These results will provide key information to interpret broad, continental-scale crustal motion patterns detected by sparse, regionally distributed GPS continuous trackers and by spaceborne instruments. This study will contribute to international programs focused on Antarctic neotectonic and global change issues.Strategies to meet these science objectives include repeat surveys of key sites in the existing TAMDEF network, extension of the array of TAMDEF sites southward about 250 km along the Transantarctic Mountains, linked measurements with the VLNDEF network, and integration of quasi-continuous trackers within the campaign network. By extending the array of bedrock sites southward, these measurements will cross gradients in predicted vertical motion due to viscoelastic rebound. The southward extension will also allow determination of the southern limit of the active Terror Rift and will provide a better baseline for constraints on any ongoing tectonic displacements across the West Antarctic rift system as a whole that might be possible using GPS data collected by the West Antarctic GPS Network. This project will also investigate unique aspects of GPS geodesy in Antarctica to determine how the error spectrum compares to mid-latitude regions and to identify the optimum measurement and data processing schemes for Antarctic conditions. The geodetic research will improve position accuracies within our network and will also yield general recommendations for deformation monitoring networks in polar regions.An education and outreach program is planned and will be targeted at non-science-major undergraduate students taking Earth System Science at Ohio State University. The objective will be to illuminate the research process for nonscientists. This effort will educate students on the process of science and inform them about Antarctica and how it relates to global science issues.