Ray equation migration of wide-angle reflections in Dabie orogenic zone

ＲａｙｅｑｕａｔｉｏｎｍｉｇｒａｔｉｏｎｏｆｗｉｄｅａｎｇｌｅｒｅｆｌｅｃｔｉｏｎｓｉｎＤａｂｉｅｏｒｏｇｅｎｉｃｚｏｎｅＸＵ－ＹＡＯＺＨＥＮＧ１）（郑需要）ＣＨＵＮ－ＹＯＮＧＷＡＮＧ２）（王椿镛）ＸＩＡＯ－ＬＩＮＧＬＡＩ１）（赖晓玲）ＸＩＡＮ...     

Robust inversion analysis of local gravity anomalies caused by geological dislocation model of faults

ＲｏｂｕｓｔｉｎｖｅｒｓｉｏｎａｎａｌｙｓｉｓｏｆｌｏｃａｌｇｒａｖｉｔｙａｎｏｍａｌｉｅｓｃａｕｓｅｄｂｙｇｅｏｌｏｇｉｃａｌｄｉｓｌｏｃａｔｉｏｎｍｏｄｅｌｏｆｆａｕｌｔｓＪＩＡＮＬＩＡＮＧＨＵＡＮＧ（黄建梁）ＣＨＯＮＧＹＡＮＧＳＨＥＮ（申...     

Application of the time-frequency polarization analysis to study the complexity of surface wave propagation

ＡｐｐｌｉｃａｔｉｏｎｏｆｔｈｅｔｉｍｅｆｒｅｑｕｅｎｃｙｐｏｌａｒｉｚａｔｉｏｎａｎａｌｙｓｉｓｔｏｓｔｕｄｙｔｈｅｃｏｍｐｌｅｘｉｔｙｏｆｓｕｒｆａｃｅｗａｖｅｐｒｏｐａｇａｔｉｏｎＨＯＮＧＣＨＥＮ（陈虹）ＺＨＯＮＧＸＩＡＮＨＵＡＮＧ（黄忠...     

Some geologic signatures of fault creep in the continental area of China

ＳｏｍｅｇｅｏｌｏｇｉｃｓｉｇｎａｔｕｒｅｓｏｆｆａｕｌｔｃｒｅｐｉｎｔｈｅｃｏｎｔｉｎｅｎｔａｌａｒｅａｏｆＣｈｉｎａＨＯＮＧＦＡＸＩＡＮＧ（向宏发）ＳＨＵＮＭＩＮＧＵＯ（虢顺民）ＷＡＮＸＩＡＺＨＡＮＧ（张晚霞）ＢＩＮＧＬＩＡＮＧＺＨＡＮ...     

Seismic activity and active faults in Huailai basin

ＳｅｉｓｍｉｃａｃｔｉｖｉｔｙａｎｄａｃｔｉｖｅｆａｕｌｔｓｉｎＨｕａｉｌａｉｂａｓｉｎＰＥＩＤＥＷＡＮＧ（王培德）ＹＵＨＯＮＧＴＩＡＮ（田玉红）ＣＨＵＮＬＡＩＬＩ（李春来）ＹＵＮＴＡＩＣＨＥＮ（陈运泰）ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｐｈｙｓ...     

Application research of seismic method in assessment of active fault

ＡｐｐｌｉｃａｔｉｏｎｒｅｓｅａｒｃｈｏｆｓｅｉｓｍｉｃｍｅｔｈｏｄｉｎａｓｅｓｍｅｎｔｏｆａｃｔｉｖｅｆａｕｌｔＭＩＮＧＣＡＩＸＵ（徐明才）ＪＩＮＧＨＵＡＧＡＯ（高景华）ＭＩＮＧＴＡＯＣＨＡＩ（柴铭涛）ＧＵＡＮＧＫＥＷＡＮＧ（王广科）ＪＩ...     

The relationship between the earthquakes of Ningbo area and the Neotectonic movement

ＴｈｅｒｅｌａｔｉｏｎｓｈｉｐｂｅｔｗｅｎｔｈｅｅａｒｔｈｑｕａｋｅｓｏｆＮｉｎｇｂｏａｒｅａａｎｄｔｈｅＮｅｏｔｅｃｔｏｎｉｃｍｏｖｅｍｅｎｔＪＩＡＧＥＮＧＣＨＥＮ１）（陈家庚）ＣＵＮＧＵＯＣＨＥＮ２）（陈存国）ＬＩＷＡＮＧ２）（王里）ＢＯ...     

Observational results of electromagnetic radiation caused by explosion of small dimension rocks in field experiments

ＯｂｓｅｒｖａｔｉｏｎａｌｒｅｓｕｌｔｓｏｆｅｌｅｃｔｒｏｍａｇｎｅｔｉｃｒａｄｉａｔｉｏｎｃａｕｓｅｄｂｙｅｘｐｌｏｓｉｏｎｏｆｓｍａｌｄｉｍｅｎｓｉｏｎｒｏｃｋｓｉｎｆｉｅｌｄｅｘｐｅｒｉｍｅｎｔｓＡＮＺＨＯＮＧＪＩＮ１）（金安忠）ＱＩＡＮ...     

Electromagnetic tomography: consistency of images and groundwater prospecting

Ｅｌｅｃｔｒｏｍａｇｎｅｔｉｃｔｏｍｏｇｒａｐｈｙ：ｃｏｎｓｉｓｔｅｎｃｙｏｆｉｍａｇｅｓａｎｄｇｒｏｕｎｄｗａｔｅｒｐｒｏｓｐｅｃｔｉｎｇＲＵＩＦＥＮＧ１）（冯锐）ＫＵＩＸＩＡＮＧＭＡ２）（马奎祥）ＨＯＮＧＧＵＯ３）（郭鸿）ＣＨＡＮＧＱＵＡＮ...     

Fractal analysis applied to faults and earthquakes——A case study of China

Ｆｒａｃｔａｌａｎａｌｙｓｉｓａｐｐｌｉｅｄｔｏｆａｕｌｔｓａｎｄｅａｒｔｈｑｕａｋｅｓ———ＡｃａｓｅｓｔｕｄｙｏｆＣｈｉｎａＪＩＡＮＷＡＮＧ（王建）ＸＩＡＯＨＵＡＺＨＵ（朱晓华）ＹＯＮＧＨＵＩＸＵ（徐永辉）ＤｅｐａｒｔｍｅｎｔｏｆＧｅｏｇ...     

Short-term precursor of the geomagnetic horizontal field transfer functions

IntroductionThe history of studying the changes in deep geoelectric conductivity of an earthquake preparation using the parameters of geomagnetic short-period variations has been about 30 years. At first, Japanese calculated the real transfer functions as well as the a and b coefficients of Parkinson vector by taking the measurement of graph and using empirical formula. There are some examples, such as the 1923 Kanto M=7.9 earthquake (Yanagihara, 1972), the 1966 Tashkent M=5.5 earthquake, t…     

地磁水平场转换函数的短期前兆

利用昌黎、白家疃1972～1997年的磁变仪资料，计算了水平场台际转换函数和单台垂直场转换函数．通过对转换函数变化全过程的分析，注意到仅仅水平场转换函数在唐山地震之前有明显的短期前兆．这给地震预报提供了一个新的可能捕捉到短期前兆的手段．      

太阳活动,磁暴与震前大气电场异常关系研究

通过对太阳活动,磁暴与大气电场异常关系的研究及１９９７年９月至１９９８年８月白家疃台大气电场和磁暴实际观测结果的分析,论述了震前观测到的大气电场负异常现象与太阳活动和磁暴现象无明显相关。     

北京大海坨4.9级地震前白家疃井地热地形变前兆异常

北京大海坨ＭＬ＝４．９地震前，白家疃地热，地形变两种观测项目，同时观测记录到明显的异常变化，具有短期和短促，突发的临震异常特点，采取针对性的分析方法，结果较好，为单台项（前兆方法）综合预报提供了震兆观测实例。     

2004年印尼8.7级强震前昌黎台的远场电性异常特征探讨

分析了在2004年12月26日印尼8.7级地震前河北昌黎台记录到的自然电位及电场异常, 结果显示昌黎台自电位、 电场正常时段观测到的半日、 半月潮汐波周期变化在震前1个多月发生畸变, 周期消失, 变化幅度相应减小, 震后快速恢复, 且潮汐波记录比震前正常时段更加清晰。 该台地电阻率的观测结果显示起始下降变化比较平缓, 震前一周左右, 变化加剧, 出现多次阶变。 究其原因, 在强震发生前断层的蠕滑作用导致孔隙压力变化, 产生一种可以在岩石中传播的应变波, 由于台站下方岩土层对小应变信号具有很好的放大作用, 所以记录到了这种小幅度的应变波, 也就是远场的静态应变效应。 随着地震临近, 应力作用加强, 远程应变波引起台站下方水位、 水化学性质以及岩石孔隙度、 渗透率等的改变, 导致电阻率、 电场大幅度的阶变, 这反映了远场应变波的动态效应。 当然就异常幅度而言, 应变波的效应还嫌弱一些, 因此昌黎台异常变化可能还叠加了震源区激发的电磁波。     

多种方法综合测定河北昌黎ML4.5地震震源深度

利用CAP、TDMT、sPL深度震相等3种方法测定河北昌黎M_L4.5地震震源深度,利用CAP方法反演得到该地震的震源机制解,拟合得到最佳震源深度为4.5 km;利用TDMT方法反演得到拟合震源深度范围为5~6 km;在震中距20~80 km范围内的台站波形数据中,CHL、BDH两个台站识别到sPL震相,基于震源机制解,计算1~16 km深度范围对应的理论波形图,与观测波形比对后得到震源深度为5 km。结果显示,3种方法的深度研究结果基本一致,结合震源尺度以及昌黎M_L3.9地震CAP、sPL计算结果认为,昌黎M_L4.5地震的震源深度应为4~6 km。     

A kind of information on short-term and imminent earthquake precursors—research on atmospheric electric field anomalies before earthquakes

The long-time practice of observational research on earthquake prediction has shown that the information on short-term and imminent earthquake precursors can hardly be detected, but it is very important for practical and effective earthquake prediction. The result of analysis and study in this paper has shown that the anomaly of quasi-static atmospheric electric field may be a kind of reliable information on short-term and imminent earthquake precursors. On such a basis, the 20 years’ continuous and reliable data of atmospheric electric field observed at the Baijiatuan seismic station are used to study the correlation between the anomalies in seismic activity and relative quiet periods bear on the occurrence of near earthquakes within 200 km range around Beijing after the Tangshan earthquake. The observational results recently reported before hand in written form and earthquakes that actually occurred in near field in corresponding time periods are compared and analyzed. The efficacy of these written prediction opinions about near earthquakes in the recent 10 years is tested. From the test results, the brilliant prospect that the anomaly of quasi-static atmospheric electric field may really become a reliable mark for making short-term and imminent earthquake predictions is discussed. Besides, as a preliminary step, some judgment indexes for predicting earthquakes by use of the observational data of atmospheric electric field before earthquakes are put forward. In the last part, it is pointed out that it would be possible to obtain more believable judgment indexes for determining the three elements of near earthquakes before greater earthquakes (M _S≥5) only if a relatively reasonable station network (2–4 stations every 10 000 km²) is deployed and further investigation is made. Contribution No. 97A0040, Institute of Geophysics, State Seismological Bureau, China. This subject is sponsored by Program No. 95-04-05-01-04, State Seismological Bureau, China.     

1998年1月10日张北-尚义6.2级地震前昌平地震台应变资料的异常变化分析

分析了昌平地震台体应变、线应变及差应变等观测资料在１９９８ 年１ 月１０日张北尚义６ ．２ 级地震前的异常变化．结果表明：该次地震前昌平台的应变观测资料出现了明显的趋势异常;体应变的异常时间与震级有较好的相关性;差应变资料显示了短临异常;由线应变资料计算的主应变方向在地震前逐渐向震中偏转; Ｍ２ 波潮汐因子也出现了明显的异常变化     

1998年1月10日张北-尚义6.2级地震前昌平地震台应变资料的异常变化分析

分析了昌平地震台体应变、线应变及差应变等观测资料在１９９８年１月１０日张北－尚义６．２级地震前的异常变化。结果表明：该次地震前昌平台的应变观测资料出现了明显的趋势异常;体应变的异常时间与震级有较发的相关性;差应变资料显示了短临异常;由线应变资料计算的主应变方向在地震前逐渐向震中偏转;Ｍ２波潮汐因子也出现了明显的异常变化。     

应用主分量分析法研究唐山Ms7.8地震前的地磁异常

应用主分量分析法对昌黎、青光、宝坻、红山等台站(1975—1977年)三年的每月五个静日地磁绝对磁场的资料及相应时间的太阳黑子相对数的资料进行计算。结果表明,第一主分量与太阳黑子相对数对应很好,相关系数为0.9以上,而第二主分量与太阳黑子相对数的相关系数为0.03左右。对于在某一固定频率而变化的地磁外源场,内外场的比例几乎恒定在一定水平上,而在唐山地震前内外场比值有明显的异常变化,笔者认为,这个恒定水平的偏离可能是由于地壳内应力不断积累导致的地下电导率的变化而引起的。用这种方法不仅可以消除地磁场的非局部变化,而且利用内外场比值的偏离或监视内场的变化可能为使用地磁场预报地震提供一个依据。