简介：作者小心地与M_L=4.0～选择了地震5.0，215在台湾区域发生在外壳中。福建数字网络记录的最大的排水量的变细特征被多分析如下获得了：记载2.07+231.1/⊿(150km≤⊿≤650km)和刻度功能的相应表示是的=，R(⊿)=3.45-231.1(1/⊿-0.01)(150km≤⊿≤650km)然后，作者用为从September1997～2005年8月在台湾区域发生在外壳中的790地震在第1997a上述公式向前带的刻度函数从福建网络与数据决定了大小和它的错误。结果显示网络的平均误差与前者是0.20并且0.18与后者。平均误差与有车站修正的后者是0.13。与台湾地震学者决定的大小相比，有前者的大小价值平均在0.50是更低的，那平均在0.08与后者是更高的。

简介：BasedonthedigitalwaveformdatarecordedbyXinjiangDigitalSeismicNetworkfortheXinyuan-HejingM_L6.8earthquakesequencesofJune30,2012,thispaperanalyzesthestressdropsofearthquakesequencesandthecorrelationcoefficientsoffocalmechanismssignificantforstrongaftershocks.Firstly,thesourceparametersoftheXinyuan-HejingM_L6.8earthquakesequencesareobtainedbyapplyingthespectrumanalysisandtheBrunessourcemodel.Then,thecorrelationcoefficientsofspectralamplitudesarecalculatedusingthelow-frequencyspectralamplituderecordedbythesamestationforthedifferentevents.Finally,basedontheresultsofthecorrelationcoefficientsofspectralamplitudes,theeventswithsimilarfocalmechanismsaregroupedusingtheclusteringmethod.Theresultsshowthat:(1)Thestressdropvaluesshowasteadytrendintheaftershocksequencecalmperiodandthestressdropvaluesshowarise-fallinstrongaftershocks.(2)Themovingaveragecorrelationcoefficientofamplitudespectrumbeginstospreadafterthemainshock.Itshowsthatthecorrelationdecreasesbetweenthemainshockandtheaftershocksinmechanisms.(3)Theresultsoffocalmechanismgroupsshowthattheearthquakesequencesaremainlystrikeslips.ThestressdistributionofthemainpressureaxisisnearlyNS,whichisthesameasthestructuralstressfield.(4)Themagnitudeandmechanismshowthatthereisanagreementbeforethestrongaftershock,whichshowsthattheregionalstressfieldisenhanced.

简介：Beforeastrongearthquake,thereisoftenaprocessofquiescenceor2absence2ofregionalseismicactivity,whichisaphenomenonthathasattractedtheattentionofmanyscholarsinChinaandothercountries(LU,etal,1985;Wesson,1973).Inthepastten-oddyears,someChineseseismologistsmade,earlierorlater,specialstudiesonthequiescenceanomalyofseismicityinsomespecifiedareasfromdifferentangles.TakingtheconvertedannualfrequencyofM=5.0earthquakesinNorthChinaregionasacharacteristicquantity,JIANGandFENG(1989)analyzedthequiescenceanomalyofseismicactivitybyfuzzyrecognition.

简介：分析了天水台数字深井水温资料在陕西石泉ML4．7级地震前的异常特征，发现在震前5天内深井水温发生大幅度的降升变化，呈负脉冲形态，表现为典型的脉冲型前兆异常形态特征。