电磁波CT揭露重大工程岩溶发育特征--以某地铁岩溶勘察为例

灰岩地区岩溶发育程度严重影响重大工程建设,以钻探为主的城市岩溶勘察,很难充分查明地下岩溶发育特征及规模,而高密度电法、浅层地震反射等其余地球物理方法因场地条件限制和干扰因素较多,在城市岩溶探测中很难实施。鉴于此,本文采用井间电磁波CT层析技术对某地铁进行岩溶探测,应用联合迭代重建技术（simultaneous iterative reconstruction technique 简称SIRT）进行反演,获取电磁波CT吸收系数等值线图,并通过吸收系数判断岩溶发育状态。研究结果表明：电磁波CT层析技术可较好揭露地下岩溶发育规模和特征,探测结果与钻孔资料揭露岩溶信息高度吻合。该方法的成功引入为重大工程岩溶探测提供了新思路,其探测成果结合钻孔信息可作为重大工程建设可靠的地质参考依据,具有较好的科学意义和推广价值。     

分形理论在地球物理中的应用

地球科学的发展离不开数理科学和信息科学的发展。以开放巨的系统为研究对象,各种子系统的综合研究和复杂性系统理论、非线性科学理论方法在21世纪得到充分的发展,具有在更高层次上进行综合和交叉研究的特点。本文简述了分形理论的方法、原理及其在地球物理研究中的应用和展望。     

Magnitude,moment, and measurement: The seismic mechanism controversy and its resolution

This paper examines the history of two related problems concerning earthquakes, and the way in which a theoretical advance was involved in their resolution. The first problem is the development of a physical, as opposed to empirical, scale for measuring the size of earthquakes. The second problem is that of understanding what happens at the source of an earthquake. There was a controversy about what the proper model for the seismic source mechanism is, which was finally resolved through advances in the theory of elastic dislocations. These two problems are linked, because the development of a physically-based magnitude scale requires an understanding of what goes on at the seismic source. I will show how the theoretical advances allowed seismologists to re-frame the questions they were trying to answer, so that the data they gathered could be brought to bear on the problem of seismic sources in new ways.     

“核特色”应用地球物理课程教学的几点建议

应用地球物理是资源勘查工程专业的一门重要必修课程。随着核资源需求与日俱增,对核资源勘查技术的要求越来越高,对应用地球物理课程教学内容也相应提出了更高的要求。为了使学生较好地掌握这门学科并使之更加适应社会发展的需要,本文通过分析目前应用地球物理课程中存在的问题,提出一些改进方法和建议,对于核地质类高校的应用地球物理课程教学内容具有一定的参考价值。     

Crustal layering, simplicity, and the oil industry: The alteration of an epistemic paradigm by a commercial environment

This paper proposes that the gradual alteration of the predominant epistemic paradigm in crustal seismology in the interwar period—namely, simplicity—came about because of the strong influence of a particular commercial environment, i.e. the oil industry. I begin by demonstrating the interwar predominance of Jeffreys’ ‘simplicity postulate’ and his probabilistic epistemology, highlighting the espousal by several seismologists (Bullen, Stoneley, Byerly), whose crustal models drew on mathematical idealisations. Next, I demonstrate that the renunciation of simplicity in the 1930s came about too quickly, and, above all, too heterodoxically to have been the result of new geological evidence. Rather, I argue, the paradigm shift among seismologists was a result of the significant rise in seismic exploration generated by the oil industry. Driven by market demands, American petroleum companies pioneered new technologies, organised research initiatives, and trained young geophysicists who, through the fusion of experimentalism and field experience, brought about fundamental progress in earthquake seismology. Remarkably, historians of science have almost entirely failed to recognise the interwar primacy of the simplicity paradigm as well as its subsequent renunciation. More importantly, they have failed to acknowledge the role the oil industry played in contributing to this renunciation and to the development of new paradigms in seismology.     

The importance of radioactivity in geoscience and mining

Almost simultaneously with Roentgen rays, natural radioactivity was discovered. Its investigation led to important fundamentals of the geosciences: petrophysics, terrestrial heat flow, isotope geology, and absolute geological chronology. In applied geophysics and geology, exploration of radioactive ores and of tectonic faults, and radiometric well loggings, are used. Production of radioactive water and mining for uranium ores are discussed, including their development (especially in the Saxon ore mountains) and the consequences on health (radon in underground air and houses). Disposal of radioactive waste is touched on briefly.     

地震CT在岩溶精细探测中的应用与探讨——以深圳地铁14号线为例

因场地条件限制和干扰因素较多,地震反射、电法等地球物理探测手段在城市岩溶探测中很难实施。利用地震波CT(computerized tomography)层析成像技术对深圳地铁14号线进行岩溶精细探测,将获取的井间地震波初至走时进行反演,并对数据处理与分析进行研究,最终获取地下介质内部波速结构,并以此判断岩溶发育状态。实验结果表明:地震CT层析成像技术能较好查明基岩面起伏形态,并能以小于1 m的分辨率精细探测地下岩溶发育规模,其探测结果与钻孔资料高度吻合。该方法的成功引入为城市轨道交通岩溶探测提供了可行性方案,其探测成果可作为重大工程建设可靠的地质参考依据,具有较好的科学意义和推广价值。     

The Physics Underlying Gutenberg-Richter in the Earth and in the Moon

The linear Gutenberg-Richter relationship is well-established. In any region of the Earth, the logarithm of the number of earthquakes, greater than any magnitude, is proportional to magnitude. This mea...