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Full-Text Articles in Physical Sciences and Mathematics

Extraction And Visualization Of Orientation Data From Virtual Geologic Surfaces With Matlab®, Avery J. Welker, John Patrick Hogan, Andreas Eckert Nov 2019

Extraction And Visualization Of Orientation Data From Virtual Geologic Surfaces With Matlab®, Avery J. Welker, John Patrick Hogan, Andreas Eckert

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

High-resolution visualization of surfaces of geologic interest, at a multitude of scales, using 3D point cloud technologies provides an opportunity to analyze spatial relationships of surfaces using orientation data. We present a MATLAB® script that produces planar geologic attitude data (e.g., strike, dip, and dip-direction data) from 3D datasets (e.g., point clouds, 3D scanning). The method utilizes Cartesian coordinates of triangular planar surfaces and converts them into matrices of conventional geologic attitude data. Spatial relationships among data points can be investigated, using polar tangent diagrams, stereographic analysis, or geologic curvature analysis. We utilize this script to create "synthetic" graphical plots …


Lithospheric Structure And Evolution Of Southern Africa: Constraints From Joint Inversion Of Rayleigh Wave Dispersion And Receiver Functions, Tuo Wang, Stephen S. Gao, Yuhang Dai, Qiuyue Yang, Kelly H. Liu Jun 2019

Lithospheric Structure And Evolution Of Southern Africa: Constraints From Joint Inversion Of Rayleigh Wave Dispersion And Receiver Functions, Tuo Wang, Stephen S. Gao, Yuhang Dai, Qiuyue Yang, Kelly H. Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

We conduct a joint inversion of teleseismic receiver functions and Rayleigh wave phase velocity dispersion from both ambient noise and earthquakes using data from 79 seismic stations in southern Africa, which is home to some of the world's oldest cratons and orogenic belts. The area has experienced two of the largest igneous activities in the world (the Okavango dyke swarm and Bushveld mafic intrusion) and thus is an ideal locale for investigating continental formation and evolution. The resulting 3-D shear wave velocities for the depth range of 0—100Â km and crustal thickness measurements show a clear spatial correspondence with known …


Crustal Azimuthal Anisotropy Beneath The Central North China Craton Revealed By Receiver Functions, Tuo Zheng, Zhifeng Ding, Jieyuan Ning, Kelly H. Liu, Stephen S. Gao, Lijun Chang, Fansheng Kong, Xiaoping Fan May 2019

Crustal Azimuthal Anisotropy Beneath The Central North China Craton Revealed By Receiver Functions, Tuo Zheng, Zhifeng Ding, Jieyuan Ning, Kelly H. Liu, Stephen S. Gao, Lijun Chang, Fansheng Kong, Xiaoping Fan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To characterize crustal anisotropy beneath the central North China Craton (CNCC), we apply a recently developed deconvolution approach to effectively remove near-surface reverberations in the receiver functions recorded at 200 broadband seismic stations and subsequently determine the fast orientation and the magnitude of crustal azimuthal anisotropy by fitting the sinusoidal moveout of the P to S converted phases from the Moho and intracrustal discontinuities. The magnitude of crustal anisotropy is found to range from 0.06 s to 0.54Â s, with an average of 0.25 ± 0.08Â s. Fault-parallel anisotropy in the seismically active Zhangjiakou-Penglai Fault Zone is significant and could …