Comprehensive Analysis Of "Huoshan Seismic Window" Based On The Dynamic Backgrounds

"Seismic window"is usually located at the special tectonic position of the geological structure unit. It is able to reflect the changes of regional stress field by the form of small earthquake and micro seismic activities, which has been generally recognized by seismological researchers. "Huoshan seismic window" located in Anhui province, as one of the major seismic windows in east China, has been widely investigated.The past study on "Huoshan seismic window" focused on the analysis of the strong earthquakes in the region and the adjacent area by using the frequency indexes. This method shows some significance of prediction, however, it is insufficient to give reasonable earthquake parameters because of its inaccurate description to the status of small earthquake activities in the window and its lower efficiency of the earthquake prediction.Further researches were given in this thesis to improve the previous corresponding simplex methods. Firstly, the tectonic characteristics and the reservoir distribution of Huoshan region were described in detail, and the tectonic relationships between our research region and level-I active blocks of China mainland were analyzed. Secondly, the three-dimensional distribution characters of Huoshan earthquake activity were summarized from earthquake precise positioning, the relationships between the small earthquake activity in the window and the regional tectonic were further analyzed. Thirdly, the window conditions of "Huoshan seismic window" were discussed, meanwhile, a new index using strain value was proposed to replace the previous frequency index, by which the characters of small earthquakes activity can be better understood. Then, the strain value achieved a better performance in the prediction efficiency, corresponding earthquakes distribution, etc. Finally, We made comprehensive statistics and analysis of the influence to the dynamic background of the "Huoshan seismic window" window anomalies from the strong earthquakes in the western tectonic association region, the moderate earthquakes in East China and its stress level fluctuations of "Huoshan seismic window". In summary, the appearance of"Huoshan seismic window"window anomalies may be influenced by various dynamic backgrounds, or be caused by itself fluctuations of stress levels in a certain period of time. Consequently, we should concern about the possibility of the moderate earthquakes in East China in the future.