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: 1643873
• 负责人: Samantha Hansen
• 金额: $ 7.19万
• 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: 2017
• 资助国家: 美国
• 起止时间: 2017-03-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1643873&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.

对拟议研究的非技术性说明：该项目将对现有地震数据应用最先进的地震成像方法，以研究冰雪覆盖的南极大陆之下地球的三维结构。 这项研究将增进对地球结构和热点以及地质学上的近代和古代裂谷系统的了解。 研究结果将有助于建立冰盖厚度变化引起的冰运动和基岩高程变化的模型。 研究结果也将有助于指导未来的地震数据收集。 研究人员将把现有的软件从罗得岛大学的高性能计算机转移到亚拉巴马的超级计算机设施。 该项目还将通过与新墨西哥州索科罗县的学生和教师接触，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，扩大公众对南极洲科学研究的了解。 来自亚拉巴马的项目人员将访问索科罗，并与新墨西哥州理工学院和索科罗高中的学生分享研究成果。 该项目还将在不断扩大的计算地震学领域培训本科生和研究生，将这些方法应用于研究南极地质学。拟议研究的技术说明：该项目力求更好地解决三维南极地幔结构和粘性，并确定稳定的东南极岩石圈内古代裂谷的位置。 为了实现这一目标，研究人员将利用全波形层析成像反演技术，该技术将联合收割机长期环境噪声数据与地震约束相结合，比传统的层析成像方法更准确地解决结构问题。 拟议的研究将使用亚拉巴马超级计算机设施和罗得岛大学开发的程序和方法完成。 新的层析成像结果将有助于评估岩石圈结构下德龙宁毛德地以及威尔克斯和极光冰下盆地在南极洲东部，以前的裂谷情节和中期岩石圈不连续性将进行探讨。 在南极洲西部，这项工作将阐明南极洲西部裂谷系统的最东端以及威德尔海内部的断裂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办法加以量化。研究人员将重点介绍南极洲的一些地区，这些地区仍然缺乏层析成像分辨率，未来的部署将提高分辨率。

项目成果

Mantle transition zone beneath West Antarctica: Expanded mapping in previously unstudied region

南极洲西部下方的地幔过渡带：在先前未研究的区域中扩大测绘

• 发表时间: 2018
• 期刊: American Geophysical Union
• 作者: Horton, A.C.;Emry, E.;Hansen, S.E.;van Wijk, J.;O'Donnell, J.P.;Brisbourne, A.;Stuart, G.W.;Anandakrishnan, S.;Aster, R.C.;Huerta, A.D.
• 通讯作者: Huerta, A.D.

Investigating ultra-low velocity zones in the southern hemisphere using an Antarctic dataset

• DOI: 10.1016/j.epsl.2020.116142
• 发表时间: 2020-04-15
• 期刊: EARTH AND PLANETARY SCIENCE LETTERS
• 影响因子: 5.3
• 作者: Hansen, Samantha E.;Carson, Sarah E.;Yu, Shule
• 通讯作者: Yu, Shule

Crustal and Upper Mantle Structure beneath the Wilkes and Aurora Subglacial Basins, East Antarctica from Full-Waveform Ambient Noise Tomography

全波形环境噪声断层扫描显示东南极洲威尔克斯和极光冰下盆地下方的地壳和上地幔结构

• 发表时间: 2019
• 期刊: American Geophysical Union
• 作者: Kumar, A.;Emry, E.;Hansen, S.
• 通讯作者: Hansen, S.

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.

Shear-wave Velocity Structure of the Crust and Upper Mantle beneath East Antarctica from Full-Waveform Ambient Noise Tomography

全波形环境噪声层析成像显示东南极洲下方地壳和上地幔的剪切波速度结构

• 发表时间: 2020
• 期刊: Scientific Committee on Antarctic Research
• 作者: Kumar, Ashish;Emry, Erica;Hansen, Samantha
• 通讯作者: Hansen, Samantha