• 责任者：Qin Fachao (School of Land and Resources ; China West Normal University ; Nanchong 637009 ; China) ; Shi Kai
• 刊名：Journal of Mountain Research
• 出版年：2013
• 卷期：31(4)
• 关键词：时间序列分析 ; time series analysis ; 余震 ; aftershocks ; 四川 ; Sichuan Province
• 页码：p.489-494
• 图表：illus., 18 refs.
• 分类号：0500
• issnNo：ISSN1008-2786
• isbnNo：CN51-1516/P

     The strong earthquake of Ms7.0 grade in April 20, 2013 in Lushan, Sichuan Province, which caused great destruction, after the main shock occurred some dense aftershocks, understanding the time variation of early aftershock contributes to the scientific guidance for post-disaster reconstruction and disaster prevention and mitiga- tion. This paper checked the time series data of aftershocks from April 20 to May 6th, 2013, according to the Chi- na Seismic Network unified earthquake catalog of National Earthquake Scientific Data Sharing Center, using the fractal box dimension method to study the fi＂actal evolution characteristics of aftershock sequences in the different magnitude threshold. The results show that, Lushan aftershock sequence of different magnitudes have shown a char- acteristic of scale invariance and self-similarity, which means that, for aftershocks above the certain magnitude threshold, the number of aftershocks within the smaller time scale and the higher time scale has the same power-law distribution. , according to fractal dimension, the number of aftershocks above a certain magnitude threshold within a future time scale can be calculated directly, which has an important practical significance in the prediction of high magnitude aftershock. The fractal box dimension of early aftershocks in Lushan with time evolution showed rapid at- tenuation trend, this characteristic has a significant difference from the Wenchuan aftershock sequence, which re- fleets the rapid energy release of Lushan earthquake, and the distribution of high-magnitude aftershocks on the time axis quickly become very sparse from the dense; since the Lushan earthquake energy release soon, undermining the self-organized critical condition, therefore, it＇ s not easy to accumulate aftershocks which induce high-magnitude af- tershoeks in the late aftershoeks. However, due to the main shock and early intensive aftershocks caused instability of the mountain structure and loose the surface soil and rock, in this area of complex geological structure, moun- tainous terrain and the unique weather and climate conditions, the risk of secondary geological disasters will be greatly amplified, particular attention should be paid to the rainfall-induced geological disasters risk of intensive rainfall during July and August.