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CAREER: (An)elastic mantle structure based on 3D wave simulations & full waveform inversion: From GLobal ADjoint models to visualization of Slabs, Plumes And Convection in MANt

职业：基于 3D 波模拟的弹性地幔结构

基本信息

批准号：
1945565
负责人：
Hatice Bozdag
金额：
$ 62.06万
依托单位：
Colorado School of Mines
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2025-06-30
项目状态：
未结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1945565&HistoricalAwards=false
关键词：
CAREER elastic mantle structure based

项目摘要

Seismic waves generated by earthquakes travel all around the globe and carry information from the deep interior of our planet. Seismologists analyze these seismic waves and make measurements compared to simulated data to illuminate the complexities of the Earth's interior. The measurements are then used in a technique called seismic tomography, similar to medical tomography, to obtain 3D CAT-scan images of the crust and mantle in terms of seismic parameters. Advances in supercomputers and numerical methods, together with the increase in the quality and amount of seismic data in recent years, have provided new opportunities to improve the resolution of tomographic images based on 3 dimensional numerical wave simulations. High-resolution present-day snapshots of Earth's interior are essential for understanding the past and present dynamics of the mantle, which shape the surface of our planet through tectonic processes such as earthquakes and volcanic activities. Higher-resolution models are also crucial for better understanding the source of earthquakes, accurately locating them, and are required from an engineering point of view to assess seismic hazard and to detect nuclear explosions. To facilitate effective exploration of Earth's mantle for research and educational activities, constructed models together with data from other disciplines will be used to design an interactive, collaborative Earth model, SPAC-MAN (Slabs, Plumes And Convection in MANtle), for visualization in virtual and augmented reality environments and planetariums. The collaboration with the Denver Museum of Nature & History will reach a range of age groups from children to adults, educating them on the interior of our planet and its dynamics while promoting STEM fields.Seismic imaging of the mantle's multi-scale structure provides fundamental constraints to frame and understand present-day mantle dynamics. Attenuation, a measure of the energy loss of seismic waves, is a key parameter to detect partial melt, thermal variations, and water content in the mantle. Since attenuation may also significantly affect arrival times of seismic phases, wavespeed and attenuation models should be constructed together simultaneously. The goal of this CAREER proposal is to investigate the multi-scale structure of the mantle based on 3D seismic wave simulations and the simultaneous construction of seismic wavespeed and attenuation models. Emerging data sets from oceans will also be explored to assimilate them in seismic tomography to specifically improve the resolution underneath oceans. Seismic tomography is at a stage where further refinements in the resolution require the use of full physics of wave propagation. Adjoint tomography, a full-waveform inversion technique, efficiently takes advantage of 3D wave simulations leading to pure data-driven seismic models of the Earth's interior avoiding commonly used approximations and corrections in classical seismic tomography. The goal of this CAREER proposal is to provide new constraints on the multi-scale (an)elastic structure of Earth's mantle based on 3D wave simulations and full-waveform inversion. To this end, (1) an anelastic global mantle model will be constructed by simultaneously inverting for anelastic and elastic parameters based on global full-waveform inversion, which will avoid bias that may come from ignoring scattering/defocusing effects. (2) multi-scale heterogeneity throughout the mantle will be investigated through their forward modeling, (3) a framework will be constructed to assimilate emerging data sets from oceans into global adjoint inversions to improve global data coverage and the resolution of oceanic plumes. The project outcomes will provide critical parameters to mineral physicists and geodynamicists to have better insight into the composition and thermal evolution of our planet, facilitating interdisciplinary research.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.

地震产生的地震波传播到地球仪的各个角落，并携带着来自地球内部深处的信息。地震学家分析这些地震波，并将测量结果与模拟数据进行比较，以阐明地球内部的复杂性。然后，测量结果被用于一种称为地震层析成像的技术，类似于医学层析成像，以获得地壳和地幔的地震参数三维CAT扫描图像。近年来，随着超级计算机和数值方法的进步，以及地震数据质量和数量的增加，为基于三维数值波动模拟的层析成像图像的分辨率的提高提供了新的机会。地球内部的高分辨率现代快照对于了解地幔过去和现在的动态至关重要，地幔通过地震和火山活动等构造过程塑造了我们星球的表面。更高分辨率的模型对于更好地了解地震源、准确定位也至关重要，从工程角度来看，也需要更高分辨率的模型来评估地震危险和探测核爆炸。为了促进对地球地幔的有效探索，用于研究和教育活动，构建的模型与来自其他学科的数据将用于设计一个交互式，协作的地球模型，SPAC-MAN（地幔中的板，羽流和对流），用于虚拟和增强现实环境和天文馆的可视化。与丹佛自然历史博物馆的合作将覆盖从儿童到成年人的一系列年龄组，教育他们了解我们星球的内部及其动力学，同时促进STEM领域。地幔多尺度结构的地震成像为框架和理解当今地幔动力学提供了基本的限制。衰减是地震波能量损失的量度，是探测地幔部分熔融、热变化和含水量的关键参数。由于衰减也可能显著影响地震相的到达时间，因此波速和衰减模型应同时构建在一起。这个CAREER计划的目标是基于三维地震波模拟和地震波速度和衰减模型的同时构建来研究地幔的多尺度结构。还将探索新出现的海洋数据集，以便在地震层析成像中吸收这些数据集，以专门提高海洋下面的分辨率。地震层析成像正处于分辨率进一步提高的阶段，需要使用波传播的完整物理学。伴随层析成像是一种全波形反演技术，它有效地利用了3D波模拟，从而产生地球内部的纯数据驱动的地震模型，避免了经典地震层析成像中常用的近似和校正。这个CAREER建议的目标是提供新的约束的多尺度（一个）弹性结构的地幔的基础上三维波模拟和全波形反演。为此，（1）将通过基于全球全波形反演同时反演滞弹性和弹性参数来构建滞弹性全球地幔模型，这将避免因忽略散射/散焦效应而可能产生的偏差。(2)将通过其正演模拟研究整个地幔的多尺度不均匀性，（3）将建立一个框架，将海洋新出现的数据集同化为全球伴随反演，以提高全球数据覆盖率和海洋羽流的分辨率。该项目的成果将为矿物物理学家和地球动力学家提供关键参数，以更好地了解地球的组成和热演化，促进跨学科研究。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。