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.

智力优势：已经提出了许多塑造南极大陆的地质过程的候选模型。为了区分它们，需要上地幔结构的详细图像;然而，南极洲下面唯一现有的大陆尺度地震结构图像缺乏足够的分辨率来描绘重要的诊断特征。利用从南极各地震网络新获得的数据，方案研究所将采用自适应参数化层析成像方法，为整个南极洲建立一个高分辨率、大陆尺度的地震速度模型。所提出的层析成像方法结合区域地震走时数据集的背景下，全球模型，以创建一个复合的大陆规模的上地幔结构模型。所提出的方法允许更好的地震射线覆盖的区域中的更精细的结构的成像，同时限制具有较少覆盖的区域中的特征的分辨率。这项研究将有助于促进对重要的全球过程的理解，如克拉通形成，造山运动，大陆裂谷和相关的岩浆活动。此外，拟议的研究将对南极科学的其他领域产生重要影响。层析成像结果提供的约束条件可用于开发描述冰盖历史和动态所需的岩石圈热模型。更广泛的影响：PI是亚拉巴马大学的一名新教员，此前曾获得美国国家科学基金会极地研究博士后研究员的资助。该项目支持的研究生是极地研究的新手。通过UA-Tuscaloosa Magnet School合作计划，PI将通过各种在线和实践活动教育K-12学生了解南极环境和相关的职业机会。亚拉巴马大学将很大一部分招生名额分配给代表性不足的群体。