Broadband Seismological Investigations of Earth Structure and Earthquake Sources

地球结构和震源的宽带地震研究

• 批准号: 1245717
• 负责人: Thorne Lay
• 金额: $ 59.34万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1245717&HistoricalAwards=false
• 关键词: Broadband; Seismological; Investigations; Earth; Structure

The UCSC seismological research program supervised by Professor Thorne Lay uses global broadband digital seismic data (as well as high-rate GPS data and tsunami recordings) to address fundamental questions about earth structure and earthquake rupture processes. Quantitative analysis of recorded wave-fields generated by earthquakes will be used to address the following fundamental questions: (1) joint inversions of high-rate GPS data, broadband seismic body waves and surface waves, and tsunami observations will be undertaken for recent huge earthquakes in Chile, Mentawai, and off-Sumatra, for the purpose of understanding how the ruptures grew and how the faults slipped in each case; (2) spectral analysis of earthquakes on and near plate boundary megathrust faults will be conducted using strong-motion and teleseismic recordings of seismic wave vibrations to further develop and test a recently introduced model of depth-dependent variations in seismic radiation from megathrust faults; (3) stacking and migration of seismograms from deep focus earthquakes will be performed to develop images of upper mantle reflectivity and heterogeneity spectrum in the vicinity of subduction zones; and (4) new stacking and migration approaches will be applied to imaging of deep mantle scattering from structures near the core-mantle boundary and near mantle down-wellings and up-wellings to better characterize the thermal and dynamical nature of these planetary features. This overall research effort will engage the PI and two graduate students in both earthquake source and earth structure research problems using quantitative analysis of various wave types generated by earthquake sources. We hope to fully characterize the depth-dependence of seismic radiation from earthquakes, and to evaluate the implications for earthquake shaking hazard. We anticipate sustaining progress in characterizing important dynamical processes associated with the Earth's major boundary layers near the surface and near the core-mantle boundary, drawing upon this information to understand the heat flow in the Earth and the dynamical processes that drive earthquakes and volcanoes at the surface.

Thorne Lay教授监督的UCSC地震研究计划使用全球宽带数字地震数据（以及高速GPS数据和海啸记录），以解决有关地球结构和地震破裂过程的基本问题。对地震产生的记录波场的定量分析将用于解决以下基本问题：（1）对高速GPS数据，宽带地震人体波和表面波和海啸观察的联合反转，将对辣椒，Mentawai，and off and ofsuptrra的最新地震进行，以了解如何在智慧的案例中进行庞大的地震。 （2）将对地震波振动的强度和远距离记录对地震层上和近板边界上的地震进行频谱分析，以进一步开发和测试最近引入的深度依赖性变化模型的地震辐射中的模型。 （3）将进行深层地震的地震图的堆叠和迁移，以开发俯冲区附近地幔反射率和异质性光谱的图像； （4）新的堆叠和迁移方法将应用于从核心隐地附近的结构和地幔下孔和向上挡板附近的结构的深幔散射的成像，以更好地表征这些行星特征的热和动力学性质。这项整体研究工作将通过对地震来源产生的各种波动类型进行定量分析，使PI和两名研究生参与地震来源和地球结构研究问题。我们希望能够充分表征地震中地震辐射的深度依赖性，并评估对地震震动危害的影响。我们预计在表征与地面附近和核心壳边界附近的地球主要边界层相关的重要动力学过程中会持续进展，从而利用这些信息来了解地球中的热流以及在表面驱动地震和火山的动态过程。