南京及邻区数字地震波速比变化特征分析
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摘要
利用2010年1月—2017年9月南京市及邻区数字化地震资料的P波和S波震相,采用单台多震和达法和单震多台和达法分别获得了各台站波速比随时间变化曲线以及南京地区波速比空间分布,结果表明:(1)南京及邻区波速比在1.6340~1.7007,各个台站出现最低值时间不同步;(2)南京区域6个地震台站波速比变化不同,六合、江宁和南京台波速比在地震发生前2年,波速比大幅度下降,然后在一段时间内保持在低值附近波动,波速比回升后,发生主震。浦口、溧水和高淳台在波速比下降区发生地震,变化趋势不明显;(3)波速比空间分布结果显示,2次地震前、后波速比空间分布的差异性明显,区域内的波速比值较均匀,高、低值的异常区显著。
Based on the P-wave and S-wave of digital seismic data from Jan.,2010 to Sep.,2017 in Nanjing and its adjacent areas,we analyzed wave velocity ratio of each station with time and the spatial distribution of the wave velocity ratio in Nanjing area by using Wadati method of single station and multi-earthquake and Wadati method of single earthquake and multi-station. The results show that:( 1) The wave velocity ratio was between 1. 6340 and 1. 7007 in Nanjing areas,the time of minimum wave velocity ratio at each station is not synchronized.( 2) The variation of wave velocity ratio of 6 seismic stations in Nanjing area is different. The wave velocity ratio of Liuhe,Jiangning,and Nanjing Stations decreased in two years before the two earthquakes in Najing area in 2016,and then kept fluctuating around low values for a period of time. After the wave velocity ratio rised again,the main shock occurred. The earthquake also occurred at the area of decresing of wave velocity ratio of Pukou,Lishui and Gaochun Stations,and the variation of wave velocity ratio of other stations is not obvious. The results of the spatial velocity distribution of the wave velocity ratio show that the spatial distribution of the wave velocity ratio before and after the two earthquakes in 2016 is obviously different. The wave velocity ratio in the study region is relatively uneven,and anomaly regions with the high and low values are significant.
Based on the P-wave and S-wave of digital seismic data from Jan.,2010 to Sep.,2017 in Nanjing and its adjacent areas,we analyzed wave velocity ratio of each station with time and the spatial distribution of the wave velocity ratio in Nanjing area by using Wadati method of single station and multi-earthquake and Wadati method of single earthquake and multi-station. The results show that:( 1) The wave velocity ratio was between 1. 6340 and 1. 7007 in Nanjing areas,the time of minimum wave velocity ratio at each station is not synchronized.( 2) The variation of wave velocity ratio of 6 seismic stations in Nanjing area is different. The wave velocity ratio of Liuhe,Jiangning,and Nanjing Stations decreased in two years before the two earthquakes in Najing area in 2016,and then kept fluctuating around low values for a period of time. After the wave velocity ratio rised again,the main shock occurred. The earthquake also occurred at the area of decresing of wave velocity ratio of Pukou,Lishui and Gaochun Stations,and the variation of wave velocity ratio of other stations is not obvious. The results of the spatial velocity distribution of the wave velocity ratio show that the spatial distribution of the wave velocity ratio before and after the two earthquakes in 2016 is obviously different. The wave velocity ratio in the study region is relatively uneven,and anomaly regions with the high and low values are significant.
引文
[1]冯德益.地震波速异常[M].北京:地震出版社,1981.
[2]隗永刚,陈学忠,郭祥云,等.庐山7. 0级地震前单台波速异常变化研究[J].地震,2014,34(2):105-114.
[3]李艳娥,王林瑛,宋美卿,等.从波速比变化看汶川与庐山地震的孕震过程[J].大地测量与地球动力学,2016,36(11):991-997.
[4]岳晓媛,武安绪,冯刚,等.首都圈中强地震前波速比时空演化特征研究[J].中国地震,2015,31(4):688-697.
[5]王小娜,刘锦.广东新丰江库区波速比变化特征研究[J].防灾减灾学报,2017,33(4):14-20.
[6]梁向军,刘林飞,李丽,等.山西地区的波速比(Vp/Vs)特征研究[J].华北地震科学,2014,32(2):20-24.
[7]张慧,李志雄,李盛.海南岛及近海波速比特征初步研究[J].地震工程学报,2018,40(3):524-534.
[8]王亚茹,王想,宫猛,等.河北及邻区平均波速比变化特征分析[J].中国地震,2016,32(4):747-755.
[9]张琳琳,高朝军.新疆天山地区的波速比异常分析[J].中国地震,2016,32(1):118-126.
[10]张洪艳,苗春兰,卢燕红,等.吉林省前郭5. 8级震群前后波速比变化特征[J].震灾防御技术,2015,10(3):605—614.
[11]王林瑛,李艳娥,郑需要,等.芦山Ms7. 0强震前单台波速比变化特征研究[J].地震学报,2014,36(1):42-58.
[2]隗永刚,陈学忠,郭祥云,等.庐山7. 0级地震前单台波速异常变化研究[J].地震,2014,34(2):105-114.
[3]李艳娥,王林瑛,宋美卿,等.从波速比变化看汶川与庐山地震的孕震过程[J].大地测量与地球动力学,2016,36(11):991-997.
[4]岳晓媛,武安绪,冯刚,等.首都圈中强地震前波速比时空演化特征研究[J].中国地震,2015,31(4):688-697.
[5]王小娜,刘锦.广东新丰江库区波速比变化特征研究[J].防灾减灾学报,2017,33(4):14-20.
[6]梁向军,刘林飞,李丽,等.山西地区的波速比(Vp/Vs)特征研究[J].华北地震科学,2014,32(2):20-24.
[7]张慧,李志雄,李盛.海南岛及近海波速比特征初步研究[J].地震工程学报,2018,40(3):524-534.
[8]王亚茹,王想,宫猛,等.河北及邻区平均波速比变化特征分析[J].中国地震,2016,32(4):747-755.
[9]张琳琳,高朝军.新疆天山地区的波速比异常分析[J].中国地震,2016,32(1):118-126.
[10]张洪艳,苗春兰,卢燕红,等.吉林省前郭5. 8级震群前后波速比变化特征[J].震灾防御技术,2015,10(3):605—614.
[11]王林瑛,李艳娥,郑需要,等.芦山Ms7. 0强震前单台波速比变化特征研究[J].地震学报,2014,36(1):42-58.