详细信息   

• 责任者：Fan Yingying (Lanzhou Institute of Seismology of China Earthquake Administration ; Lanzhou 730000 ; China) ; Du Xuebin
• 刊名：Chinese Journal of Geophysics
• 出版年：2010
• 卷期：53(12)
• 关键词：地震前兆 ; precursor ; 四川 ; Sichuan Province
• 页码：p.2887-2898
• 图表：7 illus., 58 refs.
• 分类号：0500
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

摘要

The authors studied the changes of the geo-electric and geo-magnetic fields for the M_S8.0 Wenchuan earthquake of 2008 in Sichuan Province, China, and got the following understandings: 1) significant anomalies of the geo-electric and geo-magnetic fields, which included the self-potential changes, the increased Power Spectrum Density (PSD) of the geo-electric field and the waveform distortion of the geo-magnetic field diurnal variation, were recorded; 2) in the range of about 500 km from the M_S8.0 Wenchuan earthquake, the PSD anomalies of mainly increased T<3 h low frequency components of the geo-electric and geo-magnetic fields were recorded. The mechanism for the anomalies is studied, as a result, it can be understood that in the processes of the non-linear development of numerous micro cracks and their directional arrangement in the media of the focal region before the earthquake, such influencing factors as the underground water migration and the electro-mechanical transformation function and so on induced the geo-electromagnetic anomalies, and the focal process of the earthquake and the local media action under these geo-electromagnetic stations led to the spatially, temporally complicated evolution of the geo-electromagnetic anomalies.