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Foreword

Journal of China University of Geosciences 2009年第3期20卷 493-495页

作者： jianghai xia Kansas Geological Survey The University of Kansas Lawrence KS 66047 USA

The Chinese Geophysical Society and China University of Geosciences （CUG） hosted the last three International Conferences on Environmental and Engineering Geophysics （ICEEG） on the campus of CUG in Wuhan, China, biannually from 2004 to 2008. The ICEEG has become one of the main international conferences on near-surface geophysics in the world and the most influential near-surface geophysics con- ference in China. More than 200 people from more than 10 countries attended each conference, including practitioners, academicians, researchers, and students.

关键词： International China Society Chinese three

Applications of Geophysics in Resource Detection and Environmental Protection

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Engineering 2018年第5期4卷 584-585页

作者： Suping Peng jianghai xia Jiulong Cheng State Key Laboratory of Coal Resources and Safe Mining China University of Mining and Technology Beijing 100083 China School of Earth Sciences Zhejiang University Hangzhou 310027 China

Urbanization is an inevitable trend in the modernization of human society. The Chinese government has put forward a goal for urbanization in China in 2014, which focuses on the three tasks, each containing 100 million people. In the next lOyears, China＇s urbanization process will occur at the fastest rate in her his-tory. Earth＇s near surface, which extends from the ground surface to a depth of nearly 100 m, is the most complex, sensitive, and fragile part of the planet. The near surface provides the vast majority of nec-essary materials, along with substantial space for human living. Therefore, China＇s urbanization relies on a ＂healthy＂ and sustainable near surface.

关键词：城市化中国发展现状城市发展

Heat Shielding Effects in the Earth＇s Crust

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Journal of Earth Science 2017年第1期28卷 161-167页

作者： Yixian Xu Lupei Zhu Qinyan Wang Yinhe Luo jianghai xia School of Earth Sciences Zhejiang University Hangzhou 310027 China State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan 430074 China Hubei Subsurface Multi-Scale lmaging Key Laboratory Institute of Geophysics and Geomatics China University of Geosciences Wuhan 430074 China Department of Earth and Atmospherie Sciences Saint Louis University St. Louis MO 63103 USA School of Earth Sciences China University of Geosciences Wuhan 430074 China

Knowledge of heat flow and associated variations of temperature with depth is crucial for understanding how the Earth functions. Here, we demonstrate possible heat shielding effects that result from the occurrence of mafic intrusions/layers（granulitic rocks） within a dominantly granitic middle crust and/or ultramafic intrusions/layers（peridotitic rocks） within a dominantly granulitic lower crust; heat shielding is a familiar phenomenon in heat engineering and thermal metamaterials. Simple one-dimensional calculations suggest that heat shielding due to the intercalation of granitic, granulitic and peridotitic rocks will increase Moho temperatures substantially. This study may lead to a rethinking of numerous proposed lower crustal processes.

关键词： geotherm crustal laminated structure heat shielding heat conductivity peridotitic in-trusions North Tibet magnetotelluric data.

Seismic Reflection Characteristics of Naturally-Induced Subsidence Affecting Transportation

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Journal of China University of Geosciences 2009年第3期20卷 496-512页

作者： Richard D Miller jianghai xia Don W Steeples Kansas Geological Survey The University of Kansas Lawrence KS 66047 USA Department of Geology The University of Kansas Lawrence KS 66047 USA

High-resolution seismic reflections have been used effectively to investigate sinkholes formed from the dissolution of a bedded salt unit found throughout most of Central Kansas. Surface subsidence can have devastating effects on transportation structures. Roads, rails, bridges, and pipelines can even be dramatically affected by minor ground instability. Areas susceptible to surface subsidence can put public safety at risk. Subsurface expressions significantly larger than surface depressions are consistently observed on seismic images recorded over sinkholes in Kansas. Until subsidence reaches the ground surface, failure appears to be controlled by compressional forces evidenced by faults with reverse orientation. Once a surface depression forms or dissolution of the salt slows or stops, subsidence structures are consistent with a tensional stress environment with prevalent normal faults. Detecting areas of rapid subsidence potential, prior to surface failure, is the ultimate goal of any geotechnical survey where the ground surface is susceptible to settling. Seismic reflection images have helped correlate active subsidence to dormant paleofeatures, project horizontal growth of active sinkholes based on subsurface structures, and appraise the risk of catastrophic failure.

关键词： shallow seismic reflection imaging subsidence sinkhole.

Imposing Active Sources during High-Frequency Passive Surface-Wave Measurement

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Engineering 2018年第5期4卷 685-693页

作者： Feng Cheng jianghai xia Chao Shen Yue Hu Zongbo Xu Binbin Mi Subsurface Imaging and Sensing Laboratory Institute of Geophysics and Geomatics China University of Geosciences Wuhan 430074 China School of Earth Sciences Zhejiang University Hangzhou 310027 China School of Measurement and Testing Engineering China Jiliang University Hangzhou 310018 China Department of Geosciences Boise State University Boise ID 83725 USA

Passive surface-wave utilization has been intensively studied as a means of compensating for the short-age of low-frequency information in active surface-wave measurement, In general, passive surface-wave methods cannot provide phase velocities up to several tens of hertz; thus, active surface-wave methods are often required in order to increase the frequency range, To reduce the amount of field work, we pro-pose a strategy for a high-frequency passive surface-wave survey that imposes active sources during con-tinuous passive surface-wave observation; we call our strategy ＂mixed-source surface-wave （MSW） measurement,＂ Short-duration （within 10 min） passive surface waves and mixed-source surface waves were recorded at three sites with different noise levels： namely, inside a school, along a road, and along a railway, Spectral analysis indicates that the high-frequency energy is improved by imposing active sources during continuous passive surface-wave observation, The spatial autocorrelation （SPAC） method and the multichannel analysis of passive surface waves （MAPS） method based on cross-correlations were performed on the recorded time sequences, The results demonstrate the flexibility and applicability of the proposed method for high-frequency phase velocity analysis, We suggest that it will be constructive to perform MSW measurement in a seismic investigation, rather than exclusively performing either active surface-wave measurement or passive surface-wave measurement,

关键词： Passive surface wave Active surface wave High frequency Mixed-source surface wave Spatial autocorrelation Multichannel analysis of passive surface waves

Viscoelastic representation of surface waves in patchy saturated poroelastic media

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Earthquake Science 2014年第4期27卷 421-431页

作者： Yu Zhang Yixian Xu jianghai xia Ping Ping Shuangxi Zhang School of Geodesy and Geomatics Wuhan University Key Laboratory of Geospace Environment and Geodesy Ministry of Education Institute of Geophysics and Geomatics China University of Geosciences State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Subsurface Imaging and Sensing Laboratory China University of Geosciences

Wave-induced flow is observed as the domi- nated factor for P wave propagation at seismic frequencies. This mechanism has a mesoscopic scale nature. The inhomogeneous unsaturated patches are regarded larger than the pore size, but smaller than the wavelength. Surface wave, e.g., Rayleigh wave, which propagates along the free surface, generated by the interfering of body waves is also affected by the mesoscopic loss mechanisms. Recent studies have reported that the effect of the wave-induced flow in wave propagation shows a relaxation behavior. Viscoelastic equivalent relaxation function associated with the wave mode can describe the kinetic nature of the attenuation. In this paper, the equivalent viscoelastic relaxation functions are extended to take into account the free surface for the Rayleigh surface wave propagation inpatchy saturated poroelastic media. Numerical results for the frequency-dependent velocity and attenuation and the time-dependent dynamical responses for the equivalent Rayleigh surface wave propagation along an interface between vacuum and patchy saturated porous media are reported in the low-frequency range （0.1-1,000 Hz）. The results show that the dispersion and attenuation and kinetic characteristics of the mesoscopic loss effect for the surface wave can be effectively represented in the equivalent vis- coelastic media. The simulation of surface wave propaga- tion within mesoscopic patches requires solving Blot＇s differential equations in very small grid spaces, involving the conversion of the fast P wave energy diffusion into the Blot slow wave. This procedure requires a very large amount of computer consumption. An efficient equivalent approach for this patchy saturated poroelastic media shows a more convenient way to solve the single phase visco- elastic differential equations.

关键词： Surface wave Patchy saturation Viscoelastic equivalence Approximation

Some Problems of Interpretation of Two-dimensional Magnetic Anomalies by Nonlinear Programming Methods

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Some Problems of Interpretation of Two-dimensional Magnetic ...

Effects of topography on propagation of high-frequency Love waves

作者： xia jianghai

＜正＞In this paper,some unconstrained nonlinear programming methods are made use of to solve the constrained inverse problem of two-dimensional magnetic anomalies. Since an unconstrained inverse problem was solved by...

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Effects of topography on propagation of high-frequency Love ...

The Potential of CUDA-based Acceleration of Elastic Wavefield Modeling and Inversion

信号处理在地球物理——浙江省信号处理学会2018年学术年会

作者： Chaoqiang Xi jianghai xia The School of Earth Science Zhejiang University

Multi-channel Analysis of Love Wave(MALW) is a newly developed method for near-surface structural detecting,with simpler dispersion characteristics than Rayleigh *** Rayleigh Waves,Love waves are formed by the interference of multiple reflection and refraction of SH waves and independent of P *** theory,surface wave propagation is usually strongly influenced by free surface *** study the propagation characteristics of Love Wave on complex topographic conditions for near-surface applications,we simulate Love Waves by the finite-difference method with two kinds of topographic model:depressed topographic surface models and uplifted topographic surface *** changing the slope of the topography,we study the changes of the energy,and analyze the impact of the topography change on the phase velocity dispersion *** numerical simulation results indicate that,depressed and uplifted topographies have different influence on the propagation of *** the analysis of dispersion spectrums of depressed topography model,the phase velocity of Love waves will be slightly less than theoretical velocity,especially in the low frequency *** dispersion energy was generate in the dispersion of uplifted topography *** with previous Rayleigh wave studieswith the same topography,the phase velocity of dispersion spectrums of Love Waves is more accurate.

关键词： Love waves shear-wave velocity topography

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The Potential of CUDA-based Acceleration of Elastic Wavefiel...