甘肃岷县漳县M_S6.6地震序列波速比变化特征研究
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摘要
收集了甘肃岷县漳县MS6.6地震序列固定台站和震后6个流动台站震相观测报告,提取了P波、S波走时信息,采用多台和达法计算该地震序列波速比,发现震后较强余震发生前波速比趋势性下降的特征。这对后续震情跟踪和趋势判定过程中强余震预测有一定的参考价值和指示意义。
Collecting fixed stations and six ambulatory stations observational report of MinxianZhangxian MS 6.6 earthquake sequence,extracting travel-time information of P-wave and S-wave, using the multi-station method to compute wave velocity ratio of this earthquake sequence.The results show that there is a decreasing trend of velocity ratio before strong after-shocks.It is of reference value and indicative significance on the short-imminent term prediction of strong aftershocks. Although the wave velocity ratio anomaly is still a controversial issue,domestic and foreign scholars have made some achievements in theory and practice.In 1928,the Japanese seismologists Wadati Kiyoo first proposed the calculation method of wave velocity ratio:multi-station method.In 1962,the Soviet Union scholar Semionov published the first results of velocity abnormal in Garm region,found wave velocity anomaly and wave velocity ratio anomaly before earthquake magnitude greater than 3.5.In the early 1970s,Japan,the United States and other countries have also found a lot of wave velocity anomaly before earthquake.Especially American scholar Aggarwal found the change of wave velocity ratio anomaly before several small earthquake(the maximum magnitude is 3.3)in earthquake group and proposed to explain the anomalous with DD mode.At the same time,domestic scholars got some useful results in this field.In 1970s,Feng et al.summed up in the evolution of the crust,physical properties of medium will produce a series of changes,such as the emergence of micro fracture,expansion,seismic waves through the earth's crust medium,and velocity will change accordingly,which is an important basis for the study of the wave velocity ratio of the medium.Wang et al.(2011)made a further research of variation characteristics of wave velocity ratio before and after the Wenchuan earthquake.Feng et al.(2009)studied the average wave velocity ratio in the northeastern margin of Qinghai-Tibetan Plateau,and found that there is a certain difference in the spatial distribution of wave velocity ratio.Li et al.(2006)found strong aftershock wave velocity ratio before trend decline. Based on the previous theoretical and the actual data,we conclude that the average wave velocity ratio of this sequence is 1.713,which is consistent with the results of Feng et al.(2009). It is a different levels of wave velocity ratio decline trend before the aftershocks with ML ≥3.0occurred.Most of the aftershocks with ML ≥3.0occurred in the process of the wave velocity ratio of sequence pick-up after down to the lowest,however,only a few aftershocks with ML ≥3.0occurred while wave velocity ratio in the process of down to the lowest.
Collecting fixed stations and six ambulatory stations observational report of MinxianZhangxian MS 6.6 earthquake sequence,extracting travel-time information of P-wave and S-wave, using the multi-station method to compute wave velocity ratio of this earthquake sequence.The results show that there is a decreasing trend of velocity ratio before strong after-shocks.It is of reference value and indicative significance on the short-imminent term prediction of strong aftershocks. Although the wave velocity ratio anomaly is still a controversial issue,domestic and foreign scholars have made some achievements in theory and practice.In 1928,the Japanese seismologists Wadati Kiyoo first proposed the calculation method of wave velocity ratio:multi-station method.In 1962,the Soviet Union scholar Semionov published the first results of velocity abnormal in Garm region,found wave velocity anomaly and wave velocity ratio anomaly before earthquake magnitude greater than 3.5.In the early 1970s,Japan,the United States and other countries have also found a lot of wave velocity anomaly before earthquake.Especially American scholar Aggarwal found the change of wave velocity ratio anomaly before several small earthquake(the maximum magnitude is 3.3)in earthquake group and proposed to explain the anomalous with DD mode.At the same time,domestic scholars got some useful results in this field.In 1970s,Feng et al.summed up in the evolution of the crust,physical properties of medium will produce a series of changes,such as the emergence of micro fracture,expansion,seismic waves through the earth's crust medium,and velocity will change accordingly,which is an important basis for the study of the wave velocity ratio of the medium.Wang et al.(2011)made a further research of variation characteristics of wave velocity ratio before and after the Wenchuan earthquake.Feng et al.(2009)studied the average wave velocity ratio in the northeastern margin of Qinghai-Tibetan Plateau,and found that there is a certain difference in the spatial distribution of wave velocity ratio.Li et al.(2006)found strong aftershock wave velocity ratio before trend decline. Based on the previous theoretical and the actual data,we conclude that the average wave velocity ratio of this sequence is 1.713,which is consistent with the results of Feng et al.(2009). It is a different levels of wave velocity ratio decline trend before the aftershocks with ML ≥3.0occurred.Most of the aftershocks with ML ≥3.0occurred in the process of the wave velocity ratio of sequence pick-up after down to the lowest,however,only a few aftershocks with ML ≥3.0occurred while wave velocity ratio in the process of down to the lowest.
引文
[1]李海兵,王宗秀,付小方,等.2008年5月12日汶川地震(MS8 .0)地表破裂带的分布特征[J].中国地质,2008,35(5):803-813.LI Hai-bing,WANG Zong-xiu,FU Xiao-fang,et al.The Surface Rupture Zone Distribution of the Wenchuan Earthquake(MS8 .0)Happened on May 12th,2008[J].Chinese Geology,2008,35(5):803-813.(in Chinese)
[2]冯建刚,代炜,董治平,等.青藏块体东北缘平均波速比的测定及研究[J].西北地震学报,2009,31(1):61-65.FENG Jian-gang,DAI Wei,DONG Zhi-ping,et al.Determination and Study on Average Seismic Velocity Ratio(Vp/Vs)in Northeastern Margin of Qinghai-Tibet Block[J].Northwestern Seismological Journal,2009,31(1):61-65.(in Chinese)
[3]傅征祥,程燕.北京和张家口地区地壳平均波速比的联合测定[J].地震,1988,8(4):28-34.FU Zheng-xiang,CHENG Yan.Joint Determination of Crust Wave Velocity Ratio in Beijing and Zhangjiakou Region[J].Earthquake,1988,8(4):28-34.(in Chinese)
[4]Aggarwal Y P,Sykes L R,Ambruster J,et al.PremonitoryChanges in Seismic Velocities and Prediction of Earthquakes[J].Nature,1973,241(5385):101-104.
[5]冯德益.地震波速异常[M].北京:地震出版社,1981.FENG De-yi.Anomalies of Seismic Velocity[M].Beijing:Seismological Press,1981.(in Chinese)
[6]王林瑛,李艳娥,李芳,等.汶川地震前后地震波速比和视速度变化特征的研究[J].地震学报,2011,33(1):1-14.WANG Lin-ying,LI Yan-e,LI Fang,et al.Temporal Variation of Vp/Vs,Vp and Vs before and after 2008 Wenchuan Earthquake[J].Acta Seismologica Sinica,2011,33(1):1-14.(in Chinese)
[7]黎明晓,刘杰.云南地区地震序列的波速比(Vp/Vs)异常研究[J].地震,2006,26(1):26-34.LI Ming-xiao,LIU Jie.Study on Velocity Ratio(Vp/Vs)Anomaly of Earthquake Sequences in Yunnan Region[J].Earthquake,2006,26(1):26-34.(in Chinese)
[8]黎明晓,张晓东.应用多台法测定华北地区地壳的平均波速比[J].地震,2004,24(1):163-169.LI Ming-xiao,ZHANG Xiao-dong.Determining Average Seismic Velocity Ratios(Vp/Vs)in the Curst in North China Region by Multi-station Method[J].Earthquake,2004,24(1):163 -169.(in Chinese)
[9]李善邦.中国地震[M].北京:地震出版社,1981.LI Shan-bang.Chinese Earthquake[M].Beijing:Seismological Press,1981.(in Chinese)
[10]王志铄,李源.汶川地震余震区波速比与强余震的关系[J].山西地震,2012,(1):2.WANG Zhi-shuo,LI Yuan.The Relationship between Wave Velocity Ratio and Strong Aftershocks in Wenchuan Aftershock Zone[J].Earthquake Research in Shanxi,2012,(1):2 .(in Chinese)
[11]冯建刚,蒋长胜,韩立波,等.1970年以来甘肃台网地震观测报告收集整理及其重新定位研究[J].西北地震学报,2012,34(3):289-293.FENG Jian-gang,JIANG Chang-sheng,HAN Li-bo,et al.Collection and Reestablish Work for the Earthquake Observation Reports of the Gansu Seismographic Network since 1970and Earthquake Relocation[J].Northwestern Seismological Journal,2012,34(3):289-293.(in Chinese)
[12]龙海英,聂晓红,唐兰兰.新疆乌苏5.1级地震前波速比异常震例研究[J].地震研究,2011,34(2):126-130.LONG Hai-ying,NIE Xiao-hong,TANG Lan-lan.Study of the Abnormity of Wave-velocity Ratio before MS5.1 Wusu Earthquake in Xinjiang[J].Journal of Seismological Research,2011,34(2):126-130.(in Chinese)
[13]Whitcomb J H,Garmany J D,Anderson D L.Earthquake Prediction:Variation of Seismic Velocities before the San Fernando Earthquake[J].Science,1973,180:632-641.
[14]Gupta I N.Premonitory Seismic-wave Phenomena before Earthquakes near Fairview Peak,Nevada[J].BSSA,1975,65(2):425-437.
[2]冯建刚,代炜,董治平,等.青藏块体东北缘平均波速比的测定及研究[J].西北地震学报,2009,31(1):61-65.FENG Jian-gang,DAI Wei,DONG Zhi-ping,et al.Determination and Study on Average Seismic Velocity Ratio(Vp/Vs)in Northeastern Margin of Qinghai-Tibet Block[J].Northwestern Seismological Journal,2009,31(1):61-65.(in Chinese)
[3]傅征祥,程燕.北京和张家口地区地壳平均波速比的联合测定[J].地震,1988,8(4):28-34.FU Zheng-xiang,CHENG Yan.Joint Determination of Crust Wave Velocity Ratio in Beijing and Zhangjiakou Region[J].Earthquake,1988,8(4):28-34.(in Chinese)
[4]Aggarwal Y P,Sykes L R,Ambruster J,et al.PremonitoryChanges in Seismic Velocities and Prediction of Earthquakes[J].Nature,1973,241(5385):101-104.
[5]冯德益.地震波速异常[M].北京:地震出版社,1981.FENG De-yi.Anomalies of Seismic Velocity[M].Beijing:Seismological Press,1981.(in Chinese)
[6]王林瑛,李艳娥,李芳,等.汶川地震前后地震波速比和视速度变化特征的研究[J].地震学报,2011,33(1):1-14.WANG Lin-ying,LI Yan-e,LI Fang,et al.Temporal Variation of Vp/Vs,Vp and Vs before and after 2008 Wenchuan Earthquake[J].Acta Seismologica Sinica,2011,33(1):1-14.(in Chinese)
[7]黎明晓,刘杰.云南地区地震序列的波速比(Vp/Vs)异常研究[J].地震,2006,26(1):26-34.LI Ming-xiao,LIU Jie.Study on Velocity Ratio(Vp/Vs)Anomaly of Earthquake Sequences in Yunnan Region[J].Earthquake,2006,26(1):26-34.(in Chinese)
[8]黎明晓,张晓东.应用多台法测定华北地区地壳的平均波速比[J].地震,2004,24(1):163-169.LI Ming-xiao,ZHANG Xiao-dong.Determining Average Seismic Velocity Ratios(Vp/Vs)in the Curst in North China Region by Multi-station Method[J].Earthquake,2004,24(1):163 -169.(in Chinese)
[9]李善邦.中国地震[M].北京:地震出版社,1981.LI Shan-bang.Chinese Earthquake[M].Beijing:Seismological Press,1981.(in Chinese)
[10]王志铄,李源.汶川地震余震区波速比与强余震的关系[J].山西地震,2012,(1):2.WANG Zhi-shuo,LI Yuan.The Relationship between Wave Velocity Ratio and Strong Aftershocks in Wenchuan Aftershock Zone[J].Earthquake Research in Shanxi,2012,(1):2 .(in Chinese)
[11]冯建刚,蒋长胜,韩立波,等.1970年以来甘肃台网地震观测报告收集整理及其重新定位研究[J].西北地震学报,2012,34(3):289-293.FENG Jian-gang,JIANG Chang-sheng,HAN Li-bo,et al.Collection and Reestablish Work for the Earthquake Observation Reports of the Gansu Seismographic Network since 1970and Earthquake Relocation[J].Northwestern Seismological Journal,2012,34(3):289-293.(in Chinese)
[12]龙海英,聂晓红,唐兰兰.新疆乌苏5.1级地震前波速比异常震例研究[J].地震研究,2011,34(2):126-130.LONG Hai-ying,NIE Xiao-hong,TANG Lan-lan.Study of the Abnormity of Wave-velocity Ratio before MS5.1 Wusu Earthquake in Xinjiang[J].Journal of Seismological Research,2011,34(2):126-130.(in Chinese)
[13]Whitcomb J H,Garmany J D,Anderson D L.Earthquake Prediction:Variation of Seismic Velocities before the San Fernando Earthquake[J].Science,1973,180:632-641.
[14]Gupta I N.Premonitory Seismic-wave Phenomena before Earthquakes near Fairview Peak,Nevada[J].BSSA,1975,65(2):425-437.
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