New Approach to Investigate the Seismic Velocity Structure beneath Antarctica

学术价值：已经提出了许多关于塑造南极大陆的地质过程的候选模型。要区分它们，需要上地幔结构的详细图像；然而，目前唯一存在的南极洲下地震结构的大陆尺度图像缺乏足够的分辨率来描绘重要的诊断特征。利用南极地震台网新获得的数据，PI将采用自适应参数化层析方法，建立整个南极洲高分辨率、大陆尺度的地震速度模型。所提出的层析成像方法在全球模式的背景下结合区域地震走时数据集来创建上地幔结构的复合大陆尺度模型。提出的方法允许在地震射线覆盖较好的地区成像更精细的结构，同时限制覆盖较少的地区的特征的分辨率。这项研究将有助于增进对克拉通形成、造山、大陆裂谷和相关岩浆活动等重要全球过程的理解。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可用于开发描述冰盖历史和动力学所需的岩石圈热模型。此外，气候-冰模型需要对岩石圈结构进行进一步的限制，这些模型专注于了解南极大陆的冷却历史。博主影响：PI是阿拉巴马大学的一名新教员，此前他作为国家科学基金会极地地区研究博士后研究员获得了资助。这个项目资助的研究生是极地研究的新手。通过UA-Tuscaloosa磁体学校合作项目，PI将通过各种在线和实践活动教育K-12学生关于南极环境和相关职业机会的知识。阿拉巴马大学将相当大比例的招生空间献给了代表不足的群体。

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.