CSEDI Collaborative Proposal: a multi-disciplinary investigation of slab deformation and resulting seismic anisotropy from the transition zone to the base of the mantle

CSEDI 合作提案：对板片变形和由此产生的从地幔底部过渡带的地震各向异性进行多学科研究

• 批准号: 2054951
• 负责人: Barbara Romanowicz
• 金额: $ 44.29万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2054951&HistoricalAwards=false
• 关键词: CSEDI; Collaborative; Proposal; multi; disciplinary

Over geological time scales, rocks in Earth’s deep interior flow like fluids. The deformation and advection of rocks within the Earth are concrete expressions of mantle thermal convection. Mantle convection drives plate tectonics near Earth’s surface and controls the long-term evolution of the planet. For this project, a team of scientists from different research fields - including seismology, mineral physics, and geodynamics - collaborate to better understand the nature of mantle convection. When earthquakes happen, the energy propagates through Earth’s interior in the form of seismic waves. The speed of seismic waves traveling through rocks in one direction is often different from that in another direction. This phenomenon is called seismic anisotropy. Seismic anisotropy of rocks is controlled by their mineral structure and the nature of the surrounding mantle flows. Here, the researchers use super-computers to simulate mantle flow fields. They perform mineral physics experiments to study the deformation mechanisms of mantle minerals. They analyze seismic waves to understand mantle seismic anisotropy. The predicted mantle flow fields are combined with new understanding of mineral deformation to predict seismic anisotropy, which is then compared with observations. The aim is to provide new insight into the structure and dynamics of Earth’s deep interior. This project fosters inter-disciplinary collaboration and provides support to 3 graduate students, 1 postdoctoral associate and 1 early-career scientist. Teaching materials will be produced, which will be used in undergraduate and graduate classes and in educational outreach to the public through outreach events and via the internet. Analytical and modeling software will become available to general users.Over the past few decades, seismic anisotropy has been observed mainly in Earth’s uppermost and lowermost mantle. Yet, accumulating evidence suggests the presence of significant seismic anisotropy in the transition zone and the uppermost lower mantle. The nature of uppermost mantle seismic anisotropy is relatively well established, and some consensus exists to first order on the large-scale distribution of anisotropy in D". There is, however, little consensus on the character and strength of seismic anisotropy in the mantle transition zone and the uppermost lower mantle. It remains unclear at these depths how seismic anisotropy is related to mantle flow and the deformation mechanisms of mantle minerals. Interpreting seismic observations in the context of mantle dynamics requires input from mineral physicists and geodynamicists; they can relate the seismic velocities and anisotropy to temperature, composition, and deformation of the corresponding materials. Here an interdisciplinary team of seismologists, geodynamicists, and mineral physicists aim to further advance the understanding of the seismic and viscosity structures, and the nature of mantle flow in two regions: 1) the D" layer, in continuation of their previous works; (2) the extended transition zone located at depths ranging from ~400 to 1000 km within the Earth.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.

在地质时间尺度上，地球深内部的岩石像烟道一样。地球内岩石的变形和冒险是地幔热结构的混凝土表达。地幔对话驱动地球表面附近的板块构造，并控制地球的长期演变。对于这个项目，来自不同研究领域的科学家团队（包括地震学，矿物质物理学和地球动力学）合作，以更好地了解地幔对流的性质。当地震发生时，能量以地震波的形式通过地球内部传播。地震波的速度沿岩石沿一个方向传播的速度通常与另一个方向不同。这种现象称为地震各向异性。岩石的地震各向异性受其矿物结构和周围地幔流的性质控制。在这里，研究人员使用超级计算机来模拟地幔流场。他们执行矿物质实验，以研究地幔矿物质的变形机制。他们分析地震波以了解地幔地震各向异性。预测的地幔流场与对矿物变形的新理解相结合以预测地震各向异性，然后将其与观测值进行比较。目的是提供有关地球深层内部结构和动态的新见解。该项目促进了跨学科的合作，并为3名研究生，1名博士后助理和1名早期职业科学家提供了支持。将生产教材，该教材将通过外展活动和互联网用于本科和研究生班以及向公众提供教育宣传。一般用户将可以使用分析和建模软件。在过去的几十年中，在地球上最上层和最低地幔中都观察到地震各向异性。然而，积累的证据表明过渡区和最高地幔中存在明显的地震各向异性。最高地幔的地震各向异性的性质相对良好，并且存在一些共识，即在D”中就各向异性的大规模分布进行了一项秩序。但是，在地幔过渡区中的地震偏见和较低的梅尔特尔（Seiss）无关的是，在这些深度范围内，对地震性各向异性的特征和强度几乎没有共识。地幔矿物质的流量和地幔动力学的变形机制需要矿物质学家和地球动力学家的输入。地震和粘度结构，以及两个区域的地幔流的性质：1）d“层，延续其先前的作品； （2）位于地球内约400至1000公里的深度的扩展过渡区。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响审查标准，通过评估被认为是珍贵的支持。

项目成果

Crystallographic and shape preferred orientation producing anisotropy in slates from Northern Spain

西班牙北部板岩的晶体学和形状择优取向产生各向异性

• DOI: 10.1016/j.jsg.2022.104730
• 发表时间: 2022
• 期刊: Journal of Structural Geology
• 影响因子: 3.1
• 作者: Wenk, H.-R.;Huang, J.;Devoe, M.;Gómez-Barreiro, J.;Vasin, R.;Ren, Y.;Barrios-Sánchez, S.
• 通讯作者: Barrios-Sánchez, S.

Residual strain orientation in rolled titanium determined with synchrotron X-ray Laue microdiffraction

用同步加速器 X 射线劳厄微衍射测定轧制钛的残余应变方向

• DOI: 10.1107/s1600576722011311
• 发表时间: 2023
• 期刊: Journal of Applied Crystallography
• 影响因子: 6.1
• 作者: Devoe, Michelle;Tamura, Nobumichi;Wenk, Hans-Rudolf
• 通讯作者: Wenk, Hans-Rudolf

Seismic anisotropy, dominant slip systems and phase transitions in the lowermost mantle

• DOI: 10.1093/gji/ggab278
• 发表时间: 2021-07
• 期刊: Geophysical Journal International
• 影响因子: 2.8
• 作者: B. Chandler;Li-Wei Chen;Mingming Li;B. Romanowicz;H. Wenk

Crystallographic texture formation in Fe-9wt%Si alloy during deformation and phase transition at high pressure

结晶%20织构%20形成%20in%20Fe-9wt%Si%20合金%20期间%20变形%20和%20相%20转变%20at%20高%20压力

• 发表时间: 2023
• 期刊: Geophysical journal international
• 影响因子: 2.8
• 作者: Vasin, R. N.;Kunz, M.;Wenk, H-R and
• 通讯作者: Wenk, H-R and