【作者】 贾超；

【导师】 钱荣毅；

【作者基本信息】 中国地质大学（北京） ， 地球探测与信息技术， 2011， 硕士

【摘要】 腾冲火山区是我国著名的火山区,分布有大量的第四系火山。反射地震方法较其他物探方法而言具有较高的分辨率,在研究火山构造等复杂构造方面具有优势。但是反射地震探测理论是基于层状模型的,对于火山构造等复杂构造存在一定的局限性。在火山岩区,浅层通常伴随有高速屏蔽层、地表激发接收条件复杂,使用常规二维反射地震探测技术难于获取高质量的反射地震资料。本文选择基于有限差分法的正演模拟方法针对腾冲火山区二维反射地震探测数据采集、处理、解释方面的难点开展正演模拟工作,研究火山岩区的地震波场特征。通过收集研究区的地质、电法、天然地震层析、钻孔等方面的资料,综合分析该地区的地质地球物理特征,建立了该地区的反射地震地球物理模型,并对模型进行分类总结,通过试验研究了不同模型的反射地震波场特征。利用对这些波场特征的分析研究,针对腾冲火山区二维反射地震探测采集、处理、解释方面的问题提出了改进方案。通过对腾冲地区地质、物探、钻井等资料的总结分析,提出了针对火山区的高速屏蔽厚层模型、低速高速互层模型、弯曲界面模型等反射地震模型。利用正演模型进行模拟并分析指出,在数据采集方面应加强观测系统设计工作,保证高信噪比的资料的获取,在处理方面综合利用不同偏移距的数据可以全面获取地下目的层的反射信息,在解释方面通过比较数值模拟获得的地震剖面和正演模型,指出在解释中可能存在的误区保证解释结果的准确性。结合腾冲火山区的实际情况,进行综合分析研究获得了腾冲火山区开展二维反射地震研究的工作思路,使用正演模拟改善针对复杂构造的二维反射地震探测的不足,获得了腾冲火山区的二维反射地震资料。在腾冲火山区获得二维反射地震探测资料尚属首次。更多还原

【Abstract】 Tengchong volcanic zone is famous, there distributes a large number of Quaternary volcanoes. In the study of volcanic structures and other complex structures Seismic method has advantages in terms of higher resolution. For the seismic theory is based on horizontal layered model, the application on the volcanic structures and other complex structures has some limitations. In volcanic areas, shallow shield is usually accompanied by high-speed layers, complex shooting and receiving conditions on the surface. It is difficult to obtain high-quality seismic reflection data on these areas using the conventional 2D seismic method.For the difficulty on the seismic data acquisition, processing, interpretation, we use forward modeling method base on FDM to carry out forward simulation in order to study the seismic wave field characteristics of volcanic area. We established different geophysical models by the collected geological, electrical, natural seismic tomography, drilling and other information. We show a method to improve the result about seismic data acquisition, processing and interpretation at Tengchong volcano area.We give thick high-speed layer model, low-speed high-speed inter-layer model, bending model by the summary and analysis about geological, geophysical and drilling data in this area. By Forward modeling we point out that we should have more work on the observing system design in order to get high signal to noise ratio data and processing data of different offset to get information of the under layer and comparing the difference between the section and the model to ensure the accuracy of interpretation. Assisted by forward modeling, we get 2D seismic data of Tengchong for the first time. We show a new method about studying complex structures by seismic.更多还原