简介:公元1590年7月,在甘肃临洮附近有破坏性历史地震记载“……坏城廓庐舍,压死人畜无算”。同月,青海东部的冰沟城(今乐都县东北)也因地震而城崩。在过去出版的地震目录中,均按两次地震列出,分别称为甘肃临洮5Y2级地震,震中烈度Ⅶ度:青海乐都5级地震,震中烈度Ⅵ度。根据史料考证和现场调查结果,综合分析认为,上述两次地震很有可能为同一次地震,其震中位于甘肃永靖东南的马衔山区,震中烈度达Ⅷ一Ⅸ度,震级6V2级左右,其发震构造很可能为兰州马衔山北缘断裂带的中西段。
简介:摘 要 在普通中置柜结构简单、连锁可靠、互换性高及操作使用安全方便的基础上,进行结构和功能上的创新设计。采用多项智能化技术,满足智能电网对变电站所的智能化无人值守和程序化操作。
简介:TheseismicwaveformoftheYutianMS7.3earthquake,XinjiangonFebruary12,2014wasrecordedclearlyandcompletelybytheDigitalSeismicNetworksofXinjiang,Qinghai,Tibet,andXinjiangHotanarray,sothemethodofjointlocationbyregionalseismicnetworkandseismicarraycanbeusedtoaccuratelydeterminetheearthquakesourcelocation.Thefollowingtechnologieswereusedintheprocessoflocation:(1)WeselectedseismicstationsequallylocatedaroundtheepicenteroftheMS7.3earthquakewithanaverageintervalofabout15degreesintheinitiallocation.(2)TherecordingwaveformsofYutianseismicstationwererotatedtotheradialandtangentialdirectionstopreciselyobtainthearrivaltimeofS-wavestodeterminetheepicentraldistance.(3)Thevelocitymodelwasusedinthedeterminationoflocationoftheepicenter,basedonthehistoricalrecordsofearthquakesintheareawithinaradiusof1.0°fromthesourceasthecenter,andthevelocitymodelisobtainedafterre-fittingandcalibration.(4)BasedonthewaveformrecordsoftheHotanseismicarray,themethodofwaveformbeamingwasusedtodeterminetheazimuthsandperformthecorrectionoftheepicenterlocationwiththeseazimuths.(5)Thedeterministicmethodwasusedtomeasurethesourcedepth.Finally,itisconcludedthattheYutianMS7.3mainshockhypocenterlocationis36.197°N,82.467°E,focaldepth12kmandoriginaltime17:19:48.2p.m.February12,2014.
简介:ThispapercalculatesthestaticCoulombstresschangesgeneratedbyfourearthquakesintheYutianareaduring2008~2014separately,thendiscussesthetriggeringinfluence,theiraccumulatedCoulombstresschangesandtheirinfluenceonnearbyfaults.TheresultsindicatethattheMS5.5earthquakein2011andtheM_S7.3earthquakein2014arebothintheregionswheretheCoulombstresschangeispositive,thestresschangesare0.004MPaand0.021MPa,respectively,meaningtheyaretriggeredbypriorearthquakes.TheMS6.2earthquakein2012occurredintheplacewhereCoulombstresschangewasnegative,soitispostponedbythepriorearthquakes.TheimageofCoulombstresschangesoftheMS7.3earthquakein2014isinaccordwithaftershocks(ML≥3.0)distribution,butsomeregionsonthefaultwheretheCoulombstresschangeispositivehavefewaftershocks,andstrongaftershocksmayoccuratthesedistrictsinfuture.Inaddition,thispapercalculatestheCoulombstresschangeonnearbyfaults,andfindsthattheCoulombstresschangesofdifferentelementsintheGGCfaultareverydifferent,andmustreceivestrongtriggered-influence,thoughtheresultmaybeinfluencedbytheinputfinitefaultmodel,sothereisstillalargeearthquake-risk.TheGGN,PLC,PLWandLBWfaultswerealsotriggeredbythefourearthquakesoccurringbetween2008~2014.TheirmaximumCoulombstresschangesallexceed0.002MPa,sotheyalsohaveastrongearthquakehazard.