Wavefield Imaging of the Mantle of North America with 3D, Plane-wave Migration

通过 3D 平面波偏移对北美地幔进行波场成像

• 批准号: 0951622
• 负责人: Gary Pavlis
• 金额: $ 24.24万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0951622&HistoricalAwards=false
• 关键词: Wavefield; Imaging; Mantle; North; America

This project is applying a recently developed, three-dimensional, direct wavefield imaging method to Earthscope Transportable Array (TA) data. The approach applies a series of algorithms that implement a form of three-dimensional, migration inversion. Three-component waveforms of body waves recorded by the TA are manipulated in a manner similar to seismic reflection processing to produce a three-dimensional image volume of P to S scattering strength beneath the continent. The method is being used to produce high-resolution images of the subducting lithosphere of the Juan de Fuca/Farallon system and to develop a 3D model of the geometry of that system. As the array moves eastward the method will be used to image lithospheric scale boundaries that can be applied to test models of how the Precambrian core of the continent was assembled. Technical problems being attacked to improve the capabilities of this new method are: (1) extension of the method to image S to P conversions, (2) new methods for estimating the impulse response of the medium (deconvolution), (3) improved handling of irregular data that are the norm for passive arrays, (4) improved error appraisal metrics, and (5) multiple removal. Broader impacts include support for a PhD student's research and plans to make 3D image volumes available via the web.

该项目正在将最近开发的三维直接波场成像方法应用于 Earthscope 可移动阵列 (TA) 数据。 该方法应用了一系列实现三维偏移反演形式的算法。 TA 记录的体波三分量波形以类似于地震反射处理的方式进行处理，以产生大陆下方 P 到 S 散射强度的三维图像体积。 该方法用于生成 Juan de Fuca/Farallon 系统俯冲岩石圈的高分辨率图像，并开发该系统几何形状的 3D 模型。 随着阵列向东移动，该方法将用于对岩石圈尺度边界进行成像，该边界可用于测试大陆前寒武纪核心如何组装的模型。 为了提高这种新方法的能力而解决的技术问题是：（1）将该方法扩展到图像 S 到 P 转换，（2）估计介质脉冲响应的新方法（反卷积），（3）改进处理是无源阵列标准的不规则数据，(4) 改进的错误评估指标，以及 (5) 多重去除。 更广泛的影响包括支持博士生的研究以及通过网络提供 3D 图像卷的计划。