New Approach to Investigate the Seismic Velocity Structure beneath Antarctica

研究南极​​洲下方地震速度结构的新方法

• 批准号: 1139739
• 负责人: Samantha Hansen
• 金额: $ 7.04万
• 依托单位: University of Alabama Tuscaloosa
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-01-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1139739&HistoricalAwards=false
• 关键词: New; Approach; Investigate; Seismic; Velocity

Intellectual Merit: Numerous candidate models for the geologic processes that have shaped the Antarctic continent have been proposed. To discriminate between them, detailed images of the upper mantle structure are required; however, the only existing continental-scale images of seismic structure beneath Antarctica lack sufficient resolution to delineate important, diagnostic features. Using newly available data from various Antarctic seismic networks, the PI will employ the adaptively parameterized tomography method to develop a high-resolution, continental-scale seismic velocity model for all of Antarctica. The proposed tomography method combines regional seismic travel-time datasets in the context of a global model to create a composite continental-scale model of upper mantle structure. The proposed method allows for imaging of finer structure in areas with better seismic ray coverage while simultaneously limiting the resolution of features in regions with less coverage. This research will help advance understanding of important global processes, such as craton formation, mountain building, continental rifting and associated magmatism. Additionally, the proposed research will have important impacts on other fields of Antarctic science. Constraints provided by tomographic results can be used to develop thermal models of the lithosphere needed to characterize the history and dynamics of ice sheets. Also, further constraints on lithospheric structure are required by climate-ice models, which are focused on understanding the cooling history of the Antarctic continent.Broader impacts: The PI is a new faculty member at the University of Alabama after having been funded as a National Science Foundation Postdoctoral Fellow in Polar Regions Research. The graduate student supported by this project is new to polar research. Through the UA-Tuscaloosa Magnet School partnership program, the PI will educate K-12 students about the Antarctic environment and associated career opportunities through various online and hands-on activities. University of Alabama dedicates a significant percentage of its enrollment space to underrepresented groups.

智力优点：已提出了塑造南极大陆的地质过程的众多候选模型。要区分它们，需要上地幔结构的详细图像；但是，南极下面的唯一现有的地震结构图像缺乏足够的分辨率来描述重要的诊断特征。使用来自各种南极地震网络的新可用数据，PI将采用适应性参数化的断层扫描方法来为所有南极洲开发高分辨率，大陆规模的地震速度模型。所提出的层析成像方法结合了区域地震旅行时间数据集，在全球模型的背景下，以创建上层地幔结构的复合大陆规模模型。所提出的方法允许在具有更好地震射线覆盖范围的区域中成像更精细的结构，同时限制了覆盖范围较小的地区的特征分辨率。这项研究将有助于促进对重要的全球过程的理解，例如克拉顿形成，山区建筑，大陆裂痕和相关的岩浆主义。此外，拟议的研究将对南极科学的其他领域产生重要影响。层合结果提供的约束可用于开发表征冰盖历史和动力学所需的岩石圈的热模型。同样，气候冰模型需要对岩石圈结构的进一步限制，该模型的重点是理解南极大陆的冷却历史。Broader的影响：PI是阿拉巴马大学的一名新教职员工，在被资助为一名国家科学基金会后的北极地区研究所研究员。该项目支持的研究生是极地研究的新知识。通过UA-TUSCALOOSA磁铁学校合作计划，PI将通过各种在线和动手活动来教育K-12学生有关南极环境和关联的职业机会。阿拉巴马大学将其入学空间的很大一部分用于代表性不足的群体。