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

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便携式阵列（TA）数据。 该方法应用了一系列算法，实现了一种形式的三维，迁移反演。 由TA记录的体波的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。 该方法正用于制作胡安·德富卡/法拉隆系统俯冲岩石圈的高分辨率图像，并制作该系统几何形状的三维模型。 随着阵列向东移动，该方法将用于成像岩石圈尺度边界，这些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，正在解决的技术问题是：（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）改进对作为无源阵列标准的不规则数据的处理，（4）改进误差评估度量，以及（5）多次波消除。 更广泛的影响包括支持博士生的研究，并计划通过网络提供3D图像卷。

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.