摘要
采用江苏省数字地震台网记录的地震波形资料,利用震源位移谱低频水平与拐角频率计算了2000~2010年江苏及邻近地区561个ML≥1.5中小地震视应力值。结果显示,江苏及邻近地区的地震视应力平均值为0.91 MPa,与中国大陆的平均水平相当。视应力与震级无明显的线性关系,在震级相对较大时表现出一定的高震级对应高视应力的特点。视应力高值地区主要集中在江苏中部至南黄海海域,次高值集中分布在郯庐断裂带中南段的苏鲁交界地区、安徽段固镇至定远附近地区和肥东、巢湖一带,反映了以上地区较高的地震活动水平及地壳应力状态。不同区域ML2震级档视应力的差异性基本反映了区域地质环境、构造活动等特征的差异。
Based on the earthquake data recorded by Jiangsu Digital Seismic Netw ork,we calculate apparent stress value of 561 ML≥1. 5 medium and small earthquakes in Jiangsu and its adjacent area from 2000 to 2010 by using low frequency level of source displacement spectra and corner frequency. The results shows that the average value of apparent stress of the earthquake is 0. 91 M Pa in Jiangsu and its adjacent area,and which is the same as the average value in China mainland. There is not obvious linear relation betw een apparent stress and magnitude,however,it shows that the large magnitude corresponds to the high apparent stress when the magnitude is relative large. The high value area of apparent stress is mainly concentrated from central Jiangsu to the south Yellow Sea,and the sub-high value area of apparent stress is mainly distributed at the junction of Jiangsu and Shandong Provinces,the area around Guzhen-Dingyuan of Anhui segment and the area of Feidong and Chaohu in the south middle segment of Tanlu Fault zone,which reflects the earthquake activity and the crustal stress state is higher in these areas. The difference of apparent stress of ML2 ~ 2. 9 earthquakes in different areas basically reflects the diversity of regional geological environment and tectonic activity etc..
引文
程万正,陈学忠,乔慧珍.2006.四川地震辐射能量和视应力的研究[J].地球物理学进展,21(3):692-699.
范小平,李清河,杨从杰,等.2011.长白山天池火山区介质速度非均匀性谱结构[J].地球物理学报,54(5):1215-1221.
范小平,李清河,杨从杰.2009.S波包络时间差影响因素的数值分析[J].地震学报,31(4);367-376.
范小平,李清河,杨从杰.2009.长白山天池火山区介质非均匀性[J].地球物理学报,52(10):2580-2587.
范小平,杨从杰,李清河.2013.介质非均匀性参数对散射波包络的影响[J].地球物理学进展,28(2):687-694.
龚伟,曾佐勋,王杰,等.2010.郯庐断裂带江苏段第四纪活动性研究[J].地震研究,33(1):86-92.
黄福明,易志刚.2000.地震视应变场的演化与强震发生地区的关系[J].地震学报,22(6):577-587.
江苏省地震局.1987.江苏地震志[M].北京:地震出版社.
李芳,李宇彤,刘友富.2006.视应力方法在震群性质判定中的应用研究[J].地震,6(4):45-51.
李家灵,晁洪太.1994.郯庐活断层的分段及其大震危险性分析[J].地震地质,16(2):121-126.
刘红桂,刘杰,丁页岭,等.2006.地震视应力在云南地震序列中的前兆特征[J].地震学报,28(5):462-471.
刘红桂,缪发军,吴晶.2004.场地响应、震源参数与介质衰减的同时反演[J].地震,24(4):27-36.
刘红桂,王培玲,杨彩霞,等.2007.地震视应力在地震预测中的应用[J].地震学报,29(4):437-445.
刘杰,郑斯华,黄玉龙.2003.利用遗传算法反演非弹性衰减系数、震源参数和场地响应[J].地震学报,25(2):211-218.
秦嘉政,钱晓东.2006.云南地区地震视应力的时间和空间分布研究[J].地震学报,28(3):221-229.
孙业君,黄耘,王斌,等.2014.江苏地区尾波Q值特征研究[J].地震,34(1):24-33.
万桂梅,汤良杰,金文正,等.2009.郯庐断裂带研究进展及存在问题探讨[J].地质论评,55(2):251-259.
王琼,陈学忠,王林瑛.2005.岫岩地震序列视应力变化及其预测意义[J].地震,25(2):91-97.
吴晶,顾瑾萍.2004.甘肃景泰MS5.9地震前后小地震视应力计算讨论[J].地震,24(1):170-174.
吴忠良,黄静,林碧苍.2002.中国西部地震视应力的空间分布[J].地震学报,24(3):293-301.
杨云.2007.江苏地区介质衰减及台站场地响应特征研究[D].合肥:中国科学技术大学.
Abercrombie R..1995.Earthquake Source Scaling Relationships from 1to 5 MLUsing Seismograms Recorded at 2.5km depth[J].J.G.R.,100(12):24015-24036,doi:10.1029/95JB02397.
Andrews D.J..1986.Objective Determination of Source Parameters and Similarity of Earthquakes of Different Size[J].Geophysical Monographs,37(6):259-267.
Atkinson G.M.,Mereu R.F..1992.The Shape of Ground Motion Attenuation Curves in Southeastern Canada[J].Bull.Seism.Soc.Amer.,82(5):2014-2031.
Baltay A.,Prieto G.,Beroza G.C..2010.Radiated Seismic Energy from Coda Measurements and No Scaling in Apparent Stress with Seismic Moment[J].J.Geophys.Res.,115(B8),doi:10.1029/2009JB006736.
Brune J.N..1970.Tectonic Stress and the Spectra of Seismic Shear Waves from Earthquake[J].J.Geophys.Res.,75(26):4997-5009.
Choy G.L.,Boatwright J.L..1995.Global Patterns of Radiated Seismic Energy and Apparent Stress[J].J.Geophys.Res.,100(B9):18205-18228.
Eric P.,Chael E.P..1987.Spectral Scaling of Earthquakes in the Miramichi Region of New Brunswick[J].Bull.Seism.Soc.Amer.,77(2):347-365.
Ide S.,Beroza G.C.,Prejean S.G..2003.Apparent Break in Earthquake Scaling due to Path and Site Effects on Deep Borehole Recordings[J].J.Geophys.Res.,108(B5),doi:10.1029/2001JB001617.
Ide S.,Beroza G.C..2001.Does Apparent Stress Vary with Earthquake Size[J].Geophys.Res.Lett.,28(17):3349-3352,doi:10 .1029/2001GL013106.
Mayeda K.,Walter W.R.,1996.Moment,Energy,Stress drop,and Source Spectra of Western United States Earthquakes from Regional coda Envelopes[J].J.Geophys.Res.,101(B5):11195-11208,doi:10.1029/96JB00112.
McG arr A..1999.On Relating Apparent Stress to the Stress Causing Earthquake Fault Slip[J].J.Geophys.Res.,104(B2):3003-3011.
Mori J.,Abercrombie R.E.,Kanamori H..2003.Stress Drops and Radiated Energies of Aftershocks of the 1994 Northridge,California Earthquake[J].J.Geophys.Res.,108(B11):2545,doi:10 .1029/2001JB000474.
Newman A.V.,Okal E.A..1998.Teleseismic Estimates of Radiated Seismic Energy:The E/Mo Discriminant for Tsunami Earthquakes[J].J.Geophys.Res.,103(B11):26885-26898.
Prejean S.,Ellsworth W.L..2001.Observations of Earthquake Source Parameters at 2 km depth in the Long Valley Caldera,Eastern California[J].Bull.Seism.Soc.Am.,91(2):165-177.
Wyss M.,Brunne J.N..1968.Seismic Moment,Stress,and Source Dimensions for Earthquakes in the California-Nevada Region[J].J.Geophys.Res.,73:4681-4694.
Wyss M..1970a.Stress Estimates for South American Shallow and Deep Earthquake[J].J.Geophys.Res.,75(8):1529-1544.
Wyss M..1970b.Apparent Stresses Estimates of Earthquakes on Ridges Compared to Apparent Stresses of Earthquakes in Trenches[J].Geophys.J.R.astr Soc.,19(5):479-484.