Collaborative Research: Imaging Seismic Heterogeneity within the Antarctic Mantle with Full Waveform Ambient Noise Tomography

合作研究：利用全波形环境噪声断层扫描对南极地幔内的地震非均质性进行成像

• 批准号: 1643798
• 负责人: Erica Emry
• 金额: $ 19.67万
• 依托单位: New Mexico Institute of Mining and Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-03-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1643798&HistoricalAwards=false
• 关键词: Collaborative; Research; Imaging; Seismic; Heterogeneity

Nontechnical description of proposed research: This project will apply cutting-edge seismic imaging methods to existing seismic data to study the three-dimensional structure of the Earth beneath the ice-covered Antarctic continent. The study will improve understanding of Earth structure and hotspots and geologically recent and ancient rift systems. The results will be useful for models of ice movement and bedrock elevation changes due to variation in ice sheet thickness. The results will also help guide future seismic data collection. The researchers will transfer existing software from the high-performance computers at The University of Rhode Island to the Alabama supercomputer facilities. The project will also broaden public understanding of scientific research in Antarctica by engaging with the students and teachers in Socorro County, New Mexico to discuss career opportunities in science, technology, engineering, and mathematics (STEM), the Earth Sciences, and the importance of computers in scientific research. Project personnel from Alabama will visit Socorro and share research with students at New Mexico Tech and at the Socorro High School. The project will also train undergraduate and graduate students in the expanding field of computational seismology, by applying these approaches to study Antarctic geology.Technical description of proposed research: The project seeks to better resolve the three-dimensional Antarctic mantle structure and viscosity and to identify locations of ancient rifts within the stable East Antarctic lithosphere. To accomplish this, the researchers will utilize full-waveform tomographic inversion techniques that combine long-period ambient noise data with earthquake constraints to more accurately resolve structure than traditional tomographic approaches. The proposed research will be completed using the Alabama supercomputer facilities and the programs and methodology developed at The University of Rhode Island. The new tomographic results will be useful in assessing lithospheric structure beneath Dronning Maud Land as well as the Wilkes and Aurora Subglacial Basins in East Antarctica, where previous rifting episodes and mid-lithospheric discontinuities will be explored. In West Antarctica, the work will elucidate the easternmost extent of the West Antarctic Rift System as well as rifted structure and possible compositional variations within the Weddell Sea. The accuracy of existing Antarctic seismic models will be quantified through model validation approaches. The researchers will highlight regions of Antarctica where tomographic resolution is still lacking and where future deployments would improve resolution.

拟议研究的非技术描述：该项目将把尖端的地震成像方法应用于现有的地震数据，以研究冰雪覆盖的南极大陆下地球的三维结构。这项研究将增进对地球结构和热点以及地质上现代和古代裂谷系统的了解。这一结果将对冰层运动和由于冰盖厚度变化而引起的基岩高度变化的模型有用。研究结果也将有助于指导今后的地震数据采集。研究人员将把现有的软件从罗德岛大学的高性能计算机转移到阿拉巴马州的超级计算机设施。该项目还将通过与新墨西哥州索科罗县的学生和教师讨论科学、技术、工程和数学(STEM)、地球科学以及计算机在科学研究中的重要性等方面的职业机会，扩大公众对南极洲科学研究的了解。阿拉巴马州的项目人员将访问索科罗，并与新墨西哥理工学院和索科罗高中的学生分享研究成果。该项目还将通过应用这些方法研究南极地质学，培训不断扩大的计算地震学领域的本科生和研究生。拟议研究的技术说明：该项目寻求更好地解决南极地幔的三维结构和粘性，并确定稳定的东南极岩石圈内古代裂谷的位置。为了实现这一点，研究人员将利用全波形层析成像技术，将长周期环境噪声数据与地震约束相结合，比传统的层析方法更准确地解析构造。拟议的研究将使用阿拉巴马州的超级计算机设施以及罗德岛大学开发的程序和方法来完成。新的层析成像结果将有助于评估Dronning Maud陆地以及东南极的Wilkes和Aurora冰下盆地之下的岩石圈结构，在那里将探索以前的裂谷事件和岩石圈中部不连续。在西南极，这项工作将阐明西南极裂谷系统的最东端范围，以及威德尔海内的裂谷结构和可能的成分变化。现有南极地震模型的准确性将通过模型验证方法进行量化。研究人员将重点介绍南极洲仍然缺乏断层扫描分辨率的地区，以及未来部署将提高分辨率的地区。

项目成果

Prominent thermal anomalies in the mantle transition zone beneath the Transantarctic Mountains

横贯南极山脉下方地幔过渡带的显着热异常

• DOI: 10.1130/g47346.1
• 发表时间: 2020
• 期刊: Geology
• 影响因子: 5.8
• 作者: Emry, Erica L.;Nyblade, Andrew A.;Horton, Alan;Hansen, Samantha E.;Julià, Jordi;Aster, Richard C.;Huerta, Audrey D.;Winberry, J. Paul;Wiens, Douglas A.;Wilson, Terry J.
• 通讯作者: Wilson, Terry J.