2019年11月肥乡大地电场观测数据出现异常变化,利用逐步逼近法和排除法,对观测系统及场地环境进行巡检,通过对比主、备用观测仪器同时段数据,查找本台站历史干扰数据并对比其他台站相似数据干扰特征,排除地球物理异常,判定此次数据异常变化由农田灌溉机井漏电所致.

同井安装的ZKGD3000-NT型地下水数据监测系统水温仪和SZW-1型数字式温度计在永年北杜井250 m深度进行对比观测与井水温梯度测量,结果表明,温度梯度都随着深度的增加,井水温度逐渐升高,水温与深度呈正相关,没有明显的梯度异常井段.但两者温度动态差异较大,SZW-1温度计观测结果动态稳定性高,可以判定温度22.58℃是永年井250 m深度的井水温度,基本保持稳定上升趋势,上升速率稳定;而同孔同深度安装的ZKGD3000-NT水温仪测值波动性较大,变化速率也大,呈现下降趋势或下降速率增大.

在永年北杜井250 m深度安装的ZKGD3000-NT型地下水数据监测系统水温仪和SZW-1型数字式温度计进行对比观测与井水温梯度测量.结果表明,随着深度的增加,井水温度逐渐升高,水温与深度呈正相关,温度梯度没有明显的梯度异常井段.但两者温度动态差异较大,SZW-1温度计观测结果动态稳定性高,可以判定温度22.58℃是永年井250 m深度的井水温度,基本保持稳定上升趋势,上升速率稳定;而同孔、同深度安装的ZKGD3000-NT水温仪测值波动性较大,变化速率亦大,呈现下降趋势或下降速率增大.

以肥乡地震台地电场资料为基础,对观测中常见的一些干扰和典型变化形态进行详细识别和归类,认为主要存在地电暴干扰、高压直流输电干扰、人为干扰和电极引线漏电干扰.通过对数据异常案例研究分析,当出现干扰时,认为应该遵循“逐步逼近法”和“替换法”原则.

通过分析1966年邢台5次地震的静态库仑应力触发情况发现,前2次地震对后面的地震有较好的触发,而Ms7.2以后地震的触发不理想.从而认为,随着地震的发生和震源深度的增加,岩浆活动对地壳介质的影响越来越大,地壳介质弹性性能越来越弱,即该区域浅部可以用均匀弹性半空间来近似,而深部在岩浆等因素的影响下,用均匀弹性半空间来近似存在较大的误差,不适合用弹性位错理论计算地震的触发关系.这从侧面反映了该地区岩浆活动的剧烈性和超壳断层存在的客观性.

震源机制解存在2个节面,通过地震波记录难以确定哪个节面为地震断层面.地震静态应力触发的相关研究表明,主震对后续余震有较为明显的触发作用.余震的空间分布也可以为确定震源机制节面中的断层面提供有效信息.以汶川、玉树地震为例,按照余震最大应力触发准则来确定震源机制2节面中的断层面.研究发现,采用上述准则确定的断层面与余震分布、地表观测一致.为快速判定地震断层面提供了一种途径.

利用双差定位法测得河南濮阳地区的地震的平均深度为8.4 km,由于油田地震的深度一般在6 km以内,推测该区的地震多为构造地震,油田地震只占这里地震的一小部分.利用GEPHART的方法对该区域的42个震源机制进行应力张量反演,反演出的结果显示有走滑断层的特征,最大压应力轴盯1为32°、倾伏角为3°;中等压应力轴σ2为292°、倾伏角为71°;最小压应力轴σ3为124°、倾伏角为19°;应力比R为0.6,取σ1的方向为该区的应力场方向.

Based on local records of 10 small earthquakes recorded in Handan seismic network ,focuses of the earthquakes are reloca-ted by using simplex locating method provided in MSDP software .The focus locating results and seismic reflected wave are used to calculate the crustal depth in Puyang ,Henan .The result shows the depth is about 30 .9 km .

介绍一个用DELPHI语言编写的用来处理大规模数据的程序,主要用来生成EQT目录文件、双差定位和震源机制解的输入文件.

通过对邯郸地震台网1984-2010年记录的当地及周边地震,计算当地的平均波速比及平均泊松比的值,对其间发生的ML4.0以上地震分析,并对波速比曲线及地震震级曲线进行对比分析,得出该地区平均波速比为1.691,平均泊松比为0.229,震前波速比有低值,以期通过本研究能对当地波速比对地震的约束规律提供积参考.

<正>地震活动资料表明:苏州市及周围邻近地区,历史上没有发生过5级以上地震,现代仅仅有中小震活动。已经布设有江苏省、苏州市、浙江省、上海市数字地震台网,比较而言苏州附近是全国地震台网密度

We did an experiment to study the effect of instrument piers on the seismic waveform records by setting the same type of seismometers and data acquisition devices on the three instrument piers at Wu'an seismic station,Hebei Province during Jul.,2009—Mar.,2010.The contrast experiment shows that the waveform recordings are the best when the seismometers are set in the recess of bedrock.

The Wenchuan M8 earthquake occurred on the Longmenshan fault zone.Based on field investigation of the surface rupture and focal mechanism study of the aftershocks,we studied the geological relationship of main rupture,secondary rupture and trigged rupture.The main rupture is about 200 km long which can be divided into the south part and north part.The south part consists of two parallel fault zones mainly reverse,with several parallel secondary ruptures on the hanging wall of the main fault,and the north part is a single main fault zone characterized with lateral strike slip and reverse faulting.Comparing with 300 km long aftershock distribution,the surface rupture only occupy 200 km of them,and the left 100km on the northeast of the main rupture were triggered earthquakes.The Earthquake geology results of this paper may be useful for studying the earthquake risk evolution on the Longmenshan fault system.

Based on the geological structure of Handan area of Hebei province and the observation date more than 20 years,the normal and abnormal dynamic variations of ground deformation and groundwater as well as their relationship are analyzed. The main two control factors for the ground deformation in Handan area are Taihang mountains rising at west and the continual settlement movement of the northern China plain at east,which caused deformation slan to southeast. But after regional periodic heavy rainfall the deformation slan to northwest,because of the difference of geological structure. Both are normal variations. The anomalies in the deformation and groundwater level are extructed by effective methods,the result indicats that there was a good correspondence between a part of anomalies of opposing northwest slant and northern China plain moderate and strong earthquakes. So it should not be set dowe as interference that the ground lean with a wide and periodic hesvy rainfall. In a sence,it is a factor from out side to induce ground deformation and earthquake. So we shoule attach great importance to the factor.

By using the method of correlation analysis to geomagnetic data Z21 recorded in 8 geomagnetic stations in Hebei Province from 1981 to 2006.It is found that abnormal correlation coefficient have good relationship with the earthquakes of magnitude MS≥5.0 in Hebei and neighboring area.In 26 years 18 abnormal events appeared,in which 13 events respond to MS≥5.0 earthquake in 10 months.In this way,15 earthquakes should be predicted,3 were falsed for prediction and 2 were missed.A initial and quota parameter suitable for the earthquake prediction in Hebei Province is suggested.

A lot of crustal deformation and groundwater stations in Hebei Province recorded coseismic effect when Indonesia Sumatra M8.7 earthquake occurred on Dec.,26,2004.The characteristics of coseismaic effect in the precursory data of Hebei Province are analyzed here.The results show that this earthquake might cause faulting in the mid-eastern area of Hebei Province,and led to the occurrence of Wenan M5.1 earthquake after one and a half year.

The relationship of geomagnetic Z component anomalies in Guangping Seismostation from 1982 to 2006 with Ms≥5.0 earthquakes in Hebei and its neighboring area is analyzed with loading and unloading response ratio method,ratio of daily amplitude variation method and spatial correlation analysis method.The results show that they are corresponding well.The prediction parameters that are suitable for Guangping Geomagnetic Station are presented.

Using the Sato single isotropic scattering model and the near-field digital seismic records from Hongshan seismostation in Hebei province,the variation characteristics of S-code QC value in Xingtai seismic region are studied.The relationship between the QC value and frequency is obtained: while the length of windows are 15～30 s,QC=(42.9±20.7)f(0.98±0.13),and while the length of windows are 40～60 s,QC=(103.1±27.9)f(0.85±0.08).Through analyzing the variation curves of QC along with time in different frequency point,it is found that before Longyao ML 5.0 earthquake on April 22,2002,in Xingtai seismic region,the high-frequency part of QC value changed as increasing→reducing→re-elevating→shocking pattern,and this pattern has certain referent significance for moderate-strong earthquake prediction in Xingtai area.It is also found in the research that comparing with Aki model,the Sato model is better for the S-code computation and analysis in Xingtai seismic region.

Based on Aki single scattering model,the QC values with different coda window in Handan-Xingtai area are calculated with the seismic wave data recorded by Hongshan Seismostation and Handan digital Seismic network from March of 2001 to July of 2006.The mean QC value is 78f0.92,when window length is 20s,and is 144f0.88,when window length is 40s.The Qc value is high in south and low in north.

Strong earthquakes occurred frequently in North China area in history,but it showed tranquil since 2000.In order to analyze this phenomenon,we studied the joint area of Shanxi,Hebei and Inner Mongolia,the joint area of Hebei,Shandong and Henan province,Tangshan earthquake region, Yinshan Mountain and Yanshan Mountain earthquake belt with linear probability method that based on spectral analysis of earthquake.The results show that the method has prediction ability in some extent,and the ability is tested with R-value.