Azimuthal anisotropy and attenuation structures of the Anatolian Plate

安纳托利亚板块的方位各向异性和衰减结构

• 批准号: 1833160
• 负责人: Hejun Zhu
• 金额: $ 14.52万
• 依托单位: University of Texas at Dallas
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1833160&HistoricalAwards=false
• 关键词: Azimuthal; anisotropy; attenuation; structures; Anatolian

The Anatolian Plate has been significantly modified by complex tectonic interactions among its surrounding plates. Studying the subsurface structures of the Anatolian Plate will provide a snapshot about how continental collision and subduction modify the lithosphere and its underlying asthenosphere. In addition, the interactions among these tectonic plates make Turkey one of the most seismically active regions in the world. There are several large fault zones, including the 1500 km North Anatolian Fault, which have generated large magnitude earthquakes and serious damage to the local community. In this project, the PI proposes to map seismic structures of the Anatolian Plate, which enable the investigators to test several scientific hypotheses, such as the behaviors of the North Anatolian Fault Zone and the magma chamber of volcanic fields. With the new seismic model, the team will simulate ground motions associated with a number of large magnitude earthquakes that may occur in Turkey. These predictions will provide valuable information for seismic hazard evaluation and mitigation, which will have significant social and economic impacts. This project will advance the development of a new geophysics group at UT Dallas by supporting an early career PI and one Ph.D. graduate student. Results from this project will be disseminated via peer-reviewed publications, presentations at national meetings, as well as an online tomographic model visualization platform.With the support of this project, the PI's team will develop a new tomographic model for the Anatolian Plate, which includes 3-D variations in seismic velocities, azimuthal anisotropy and shear attenuation. Full waveform inversion, an advanced imaging technology which takes complicated wave physics into account, will be used to better extract quantitative information for the Earth's materials. By jointly interpreting velocities and azimuthal anisotropy, the team will test the following the following questions: (1) Is the North Anatolian Fault Zone a lithospheric or crustal scale transform fault? (2) Are there lower crust channel flows underneath the Anatolian Plate? (3) How do the mantle flows respond to the westward extrusion and counterclockwise rotation of the Anatolian Plate? Furthermore, considering different sensitivities of attenuation and velocity to the physical states of the crustal and mantle materials, joint interpretation of these results will help to better delineate the morphology of magma chambers, and detect potential partial melt underneath the Central and Eastern Anatolian Volcanic Fields. Testing these scientific hypotheses will improve our knowledge on how continental collision and subduction modify the Anatolian lithosphere and asthenosphere.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

安纳托利亚板块因其周围板块之间复杂的构造相互作用而发生了显着改变。研究安纳托利亚板块的地下结构将提供有关大陆碰撞和俯冲如何改变岩石圈及其底层软流圈的快照。此外，这些构造板块之间的相互作用使土耳其成为世界上地震最活跃的地区之一。有多条大型断裂带，其中包括1500公里的北安纳托利亚断裂带，曾产生过特大地震，对当地社区造成严重破坏。在这个项目中，PI建议绘制安纳托利亚板块的地震结构图，这使得研究人员能够测试一些科学假设，例如北安纳托利亚断层带和火山场岩浆室的行为。利用新的地震模型，该团队将模拟与土耳其可能发生的多次大地震相关的地面运动。这些预测将为地震灾害评估和缓解提供有价值的信息，从而产生重大的社会和经济影响。该项目将通过支持一名早期职业 PI 和一名博士来推动 UT 达拉斯分校新地球物理学小组的发展。研究生。该项目的结果将通过同行评审出版物、国家会议上的演示以及在线断层扫描模型可视化平台进行传播。在该项目的支持下，PI 团队将为安纳托利亚板块开发新的断层扫描模型，包括地震速度、方位角各向异性和剪切衰减的 3-D 变化。全波形反演是一种考虑了复杂波动物理的先进成像技术，将用于更好地提取地球物质的定量信息。通过联合解释速度和方位各向异性，团队将检验以下问题：（1）北安纳托利亚断裂带是岩石圈还是地壳尺度转换断裂？ (2) 安纳托利亚板块下方是否存在下地壳通道流？ （3）地幔流如何响应安纳托利亚板块的向西挤压和逆时针旋转？ 此外，考虑到衰减和速度对地壳和地幔物质物理状态的不同敏感性，对这些结果的联合解释将有助于更好地描绘岩浆房的形态，并检测安纳托利亚中部和东部火山田下方潜在的部分熔融。测试这些科学假设将提高我们对大陆碰撞和俯冲如何改变安纳托利亚岩石圈和软流圈的了解。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

High Vp/Vs ratio in the crust and uppermost mantle beneath volcanoes in the Central and Eastern Anatolia

• DOI: 10.1093/gji/ggy253
• 发表时间: 2018-06
• 期刊: Geophysical Journal International
• 影响因子: 2.8
• 作者: Hejun Zhu

Estimating P Wave Velocity and Attenuation Structures Using Full Waveform Inversion Based on a Time Domain Complex‐Valued Viscoacoustic Wave Equation: The Method

使用基于时域复数的全波形反演估计 P 波速度和衰减结构 - 值粘声波方程：该方法

• DOI: 10.1029/2019jb019129
• 发表时间: 2020
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: Yang, Jidong;Zhu, Hejun;Li, Xueyan;Ren, Li;Zhang, Shuo
• 通讯作者: Zhang, Shuo