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.

Anatolian板已通过其周围板之间的复杂构造相互作用进行了显着修饰。研究Anatolian板的地下结构将提供一个快照，以了解大陆碰撞和俯冲如何修饰岩石圈及其潜在的软圈。此外，这些构造板之间的相互作用使土耳其成为世界上最活跃的地区之一。有几个大型断层区，包括北安纳托利亚断层1500公里，这些断层造成了巨大的地震和对当地社区的严重破坏。在该项目中，PI建议绘制安纳托利亚板块的地震结构，这使研究人员能够测试几种科学的假设，例如北安纳托利亚断层区的行为和火山场的岩浆室。借助新的地震模型，该团队将模拟与土耳其可能发生的许多大量地震相关的地面运动。这些预测将为地震危害评估和缓解提供宝贵的信息，这将产生重大的社会和经济影响。该项目将通过支持早期职业PI和一位博士学位来推动UT达拉斯新的地球物理小组的发展。研究生。该项目的结果将通过经过同行评审的出版物，全国会议上的演示以及在线层析模型可视化平台进行传播。在该项目的支持下，PI团队将开发一个新的Anatolian板块模型，该模型包括Anatolian Plate，其中包括地震速度，Azimuthal Anisotropery和Shear shear and shear and and seisticities seist速度变体。全波形倒置，一种高级成像技术，考虑了复杂的波形物理，将用于更好地提取地球材料的定量信息。通过共同解释速度和方位角各向异性，该团队将测试以下问题：（1）北安纳托利亚断层区是岩石圈或地壳量表变换故障吗？ （2）在安纳托利亚板下方是否有下层地壳通道流？ （3）地幔流如何响应Anatolian板的向西挤压和逆时针旋转？ 此外，考虑到对地壳和地幔材料的物理状态的衰减和速度的不同敏感性，对这些结果的联合解释将有助于更好地描述岩浆室的形态，并在中部和东部的安纳托利亚射线场下方检测潜在的部分融化。对这些科学假设进行检验将提高我们对大陆碰撞和俯冲如何修改Anatolian岩石圈和运动圈的知识。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛影响的评估标准通过评估来获得支持的。

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