用近垂直地震反射方法研究莫霍面的特征与成因

THE STUDY OF MOHO CHARACTERISTICS AND FORMATION BY NEARLY VERTICALSEISMIC REFLECTION METHOD

利用近垂直地震反射方法研究了在中国满洲里－绥芬河地学断面域内泰康－哈尔滨约１３０ｋｍ范围内地壳结构和莫霍面特征．通过数据采集，定量处理和综合分析，得到以下认识：在野外观测中激发井深和震源能量是主要参数；在资料处理中速度分析与共反射点分布的处理是主要技术．分析莫霍震相可以得到它的层状与似层状内部结构以及起伏、断裂等外形特征．利用傅立叶谱、时频分析与瞬时信息可更细致地研究莫霍特征．影响莫霍特征与成因的因素主要为分异作用、地幔对流、相变、地球转动和板块运动；其中地幔对流和相变是形成莫霍的主要因素．

Nearly vertical seismic reflecgion method is the main one to research for Moho.In the field observation the explosive well depth and the seismic source energy arethe major factors. In the data processing velocity analysis and the processing ofcommon reflecgion pointS distribugion are the major techniques. By the analysis ofMoho seismic waves phases we can acquire not only the interior structure of itsstratification and resemble stratification but also the exterior characteristics of itsfluctuations, faults and so on. Applying Fourier spectrum, bine-frequency analysis,instantaneous information we can exactly research for Moho interior characteristics.The five factors, which Put different emphases and have a fundamental effect onMoho characteristics and formation on the whole, are differentiation reaction, mantleconvection, phase variation, earth rotation, plate movement Mantle convection andphase variation are the major factors of Moho formation.