各向异性地球物理与矢量场

Anisotropic geophysics and vector field

地球介质电阻率、极化率、速度和品质因子等物理性质的各向异性是广泛存在且被证明不可忽视的,因此,在地震学和固体地球电磁场研究中,各向异性问题的讨论由来已久,且是最近十多年来的前沿领域与热点.最近几年随着信息技术的快速发展,以及地球物理从一维到二维、三维和不同高度的矢量、立体张量观测技术的发展,使得研究更复杂的各向异性介质及地球物理响应矢量数据的发掘和应用成为可能,从而给现有的地球物理理论、方法和技术带来了严峻的挑战.尤其信息科学领域云计算技术和大数据研究与应用的蓬勃兴起,大量地球物理观测数据的利用和共享成为一种发展趋势.第567次香山科学会议"各向异性地球物理与矢量场技术"旨在通过对国内外各向异性地球物理和矢量场前沿研究的介绍、分析,会同后续云计算、地震学与矢量地球物理场观测仪器与技术3篇专业文章的详细展开,发掘、总结各向异性理论方法与矢量场研究中急需解决的关键科学和技术问题,以促进基础性、共性问题的攻关与探索.

It has been proved that the physical anisotropies of earth medium, such as resistivity, electric susceptibility, velocity, and quality factor, et al., exist and can＇t be ignored. For this reason, researches on anisotropy began tens of years ago and now become a hotspot in the field of seismology and geo-electromagnetism in recent years. Promoted by development of information sciences and technology, especially driven by technological progresses of sensor, storage and communication of big dataset, the observations of geophysical field have been upgraded to 2-and 3-dimensional, multi-component vector and tensor measurements at different elevations and spatial sizes, such as 6-component seismic and 5-component MT acquisition provided the possibilities of anisotropic inversion and more precise prediction on physical parameters in geosciences. However, serious challenges have been faced by the traditional geophysics, just because the theoretical principles, methods and techniques of geophysics were built on the basis of scalar observation, and massive vector data are observed and their sharing and utilization become an incontrovertible trend. Thus, in this No.567 Xiangshan-Science Conferences, the progresses and problems in the study of anisotropic geophysics and vector field were introduced and analyzed according to 4 sections. First, different scale and types of vibrations from 6-component earthquake, 3-component seismic exploration and micro-seismic monitoring, and the relations in between are presented and discussed. Secondly, numerical simulations and inversions of resistivity anisotropy are given more discussions; especially on the non-uniqueness of anisotropic inversions for apparent resistivity, tensor observation and azimuthal acquisition were also addressed. Thirdly, the joint geophysical measurements from different altitudes, including well logging, underground geophysical prospecting, airborne and satellite geophysical observations are expected to be used on land, in the ocean and in the air. Finally, instruments of vector seismic sensing and tensor MT and CSAMT, processing techniques of vector signals and software system, communication and storage of big geophysical datasets, including advanced technologies on compressed sensing, were introduced respectively. All these presentations could not be covered in detail within one paper, though, the basic scientific and technological problems about computational geophysics, active or passive seismology, and anisotropic electromagnetism will be focused on, while the detailed discussions on different geophysical fields will follow in other papers, so that the issues on the fundaments and generality of anisotropic geophysics could be studied extensively in the future.