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:ThenorthernmarginoftheSouthChinaSea,asatypicalextensionalcontinentalmargin,hasrelativelystrongintraplateseismicity.ComparedwiththeactivezonesofNanaoIsland,Yangjiang,andHeyuan,seismicityinthePearlRiverEstuaryisrelativelylow.However,aML4.0earthquakein2006occurrednearDanganIsland(DI)offshoreHongKong,andthissitewasadjacenttothesourceofthehistoricalM5.8earthquakein1874.TorevealtheseismogenicmechanismofintraplateearthquakesinDI,wesystematicallyanalyzedthestructuralcharacteristicsinthesourceareaofthe2006DIearthquakeusingintegrated24-channelseismicprofiles,onshore–offshorewide-angleseismictomography,andnaturalearthquakeparameters.WeascertainedthelocationsofNW-andNE-trendingfaultsintheDIseaandfoundthattheNE-trendingDIfaultmainlydippedsoutheastatahighangleandcutthroughthecrustwithanobviouslow-velocityanomaly.TheNW-trendingfaultdippedsouthwestwithasimilarhighangle.The2006DIearthquakewasadjacenttotheintersectionoftheNE-andNW-trendingfaults,whichsuggestedthattheintersectionofthetwofaultswithdifferentstrikescouldprovideafavorableconditionforthegenerationandtriggeringofintraplateearthquakes.Crustalvelocitymodelshowedthatthehigh-velocityanomalywasimagedinthewestofDI,butadistinctentitywithlow-velocityanomalyintheuppercrustandhigh-velocityanomalyinthelowercrustwasfoundinthesouthofDI.Boththe1874and2006DIearthquakesoccurredalongtheedgeofthedistinctentity.Twoverticalcross-sectionsnearlyperpendiculartothestrikesoftheintersectingfaultsrevealedgoodspatialcorrelationsbetweenthe2006DIearthquakeandthelowtohighspeedtransitioninthedistinctentity.Thisresultindicatedthatthetransitionalzonemightbeaweaklystructuralbodythatcanstorestrainenergyandreleaseitasabrittlefailure,resultinginanearthquake-pronearea.
简介:BasedonthedigitalwaveformdatarecordedbyXinjiangDigitalSeismicNetworkfortheXinyuan-HejingM_L6.8earthquakesequencesofJune30,2012,thispaperanalyzesthestressdropsofearthquakesequencesandthecorrelationcoefficientsoffocalmechanismssignificantforstrongaftershocks.Firstly,thesourceparametersoftheXinyuan-HejingM_L6.8earthquakesequencesareobtainedbyapplyingthespectrumanalysisandtheBrunessourcemodel.Then,thecorrelationcoefficientsofspectralamplitudesarecalculatedusingthelow-frequencyspectralamplituderecordedbythesamestationforthedifferentevents.Finally,basedontheresultsofthecorrelationcoefficientsofspectralamplitudes,theeventswithsimilarfocalmechanismsaregroupedusingtheclusteringmethod.Theresultsshowthat:(1)Thestressdropvaluesshowasteadytrendintheaftershocksequencecalmperiodandthestressdropvaluesshowarise-fallinstrongaftershocks.(2)Themovingaveragecorrelationcoefficientofamplitudespectrumbeginstospreadafterthemainshock.Itshowsthatthecorrelationdecreasesbetweenthemainshockandtheaftershocksinmechanisms.(3)Theresultsoffocalmechanismgroupsshowthattheearthquakesequencesaremainlystrikeslips.ThestressdistributionofthemainpressureaxisisnearlyNS,whichisthesameasthestructuralstressfield.(4)Themagnitudeandmechanismshowthatthereisanagreementbeforethestrongaftershock,whichshowsthattheregionalstressfieldisenhanced.
简介:摘要:受电弓是电力牵引机车从接触网取得电能的电气设备,安装在机车或动车车顶上。受电弓可分单臂和双臂两种,均由滑板、上框架、下臂杆、底架、升弓弹簧、传动气缸、支撑绝缘子等部件组成。本文主要介绍了CRH5型动车组受电弓结构原理和工作原理,并结合实际检修经验,对受电弓高级修检修技术进行分析。
简介:Beforeastrongearthquake,thereisoftenaprocessofquiescenceor2absence2ofregionalseismicactivity,whichisaphenomenonthathasattractedtheattentionofmanyscholarsinChinaandothercountries(LU,etal,1985;Wesson,1973).Inthepastten-oddyears,someChineseseismologistsmade,earlierorlater,specialstudiesonthequiescenceanomalyofseismicityinsomespecifiedareasfromdifferentangles.TakingtheconvertedannualfrequencyofM=5.0earthquakesinNorthChinaregionasacharacteristicquantity,JIANGandFENG(1989)analyzedthequiescenceanomalyofseismicactivitybyfuzzyrecognition.