简介:野外地质地貌调查表明,龙陵-瑞丽断裂(南支)北段是以左旋走滑为主兼具一定正断分量的区域性活动断裂。断裂晚更新世以来的平均水平滑动速率为2.2mm/a,平均垂直滑动速率为0.6mm/a;全新世以来的平均水平滑动速率为1.8—3.0mm/a,平均垂直滑动速率为0.5mm/a。断裂在晚更新世以来的滑动速率在不同的时间尺度上变化不大,反映出该断裂晚更新世以来的活动强度比较稳定。利用Poisson模型、Lognormal模型、BPT模型三种概率模型计算获得未来50a强震发震概率分别是:6.32%、0.08%、0.05%;三种模型分别取权重0.28、0.36、0.36,获得龙陵-瑞丽断裂北段未来50a特征地震发震概率为1.82%。
简介:Intheestimationofseismictendency,usingGutenberg-Richter¢sb-valueandusingHurstexponentaretwocom-monlyusedmethods.Basedonthefractalgeometryofearthquaketimeseries,wepointoutthatthesetwomethodscorrelatetoeachother.IntheperspectiveoffractionalBrownianmotion(FBM),anearthquakesequencewithb>3/4andthatwithb<3/4havedifferentdynamicproperties.
简介:Basedonisotropiclinearporoelastictheoryandundertheundrainedcondition,wesummarizethreeequationsconnectingtheSkempton’scoefficientBwiththegroundwaterlevel.Afteranalysis,weproposeamethodtocalculatetheSkempton’scoefficientBaccordingtotherelationshipbetweenwaterlevelandtidalstrain.WiththismethodwecangetthevalueofBwithouttheearthquakeoccurrence,whichcanprovidethehighfrequencywavesforresearch.Besides,wecanalsogetthein-suitSkempton’scoefficientBwithouttheexperimentofrockphysics.Inaddition,weanalyzetheobserveddataofChangpingstationrecordedingroundwatermonitoringnetwork(abv.,GMN)beforeandaftertheWenchuanMS8.0withthismethod,andfindoutthere’saslightchangeofthevalueofBaftertheseismicwavespassedby,whichimpliesthatthepropagationofseismicwavesmayhavebroughtsomevariationstotheporoelasticmediumofthewell.
简介:Inthisstudy,weadoptanimprovedBayesianapproachbasedonfree-knotB-splinebasestostudythespatialandtemporaldistributionoftheb-value.SynthetictestsshowthattheimprovedBayesianapproachhasasuperiorperformancecomparedtotheBayesianapproachaswellasthewidelyusedmaximumlikelihoodestimation(MLE)methodinfittingtherealvariationofb-values.WethenapplytheimprovedBayesianapproachtoNorthChinaandfindthattheb-valuehasaclearrelevancetoseismicity.Temporalchangesofb-valuesarealsoinvestigatedintwospecificareasofNorthChina.Weinterpretsharpdecreasesintheb-valuesasusefulmessagesinearthquakehazardanalysis.
简介:TheeffectsofmagnituderoundingandofthepresenceofnoiseintheroundedmagnitudesontheestimationoftheGutenberg–Richterb-valueareexplored,andthewaystocorrectfortheseeffectsareproposed.Fortypicalvalues,b=1androundingintervalDM=0.1,theroundingerrorisapproximately-10-3anditcanbecorrectedtoanegligibleapproximately-10-5.Forthesametypicalvalues,theeffectofnoisecanbelarger,dependingonthecharacteristicsofthenoisedistribution;fornormallydistributednoisewithstandarddeviationr=0.1,thecorrectb-valuemaybeunderestimatedbyafactor*0.97.
简介:AmodelofseismicitywithfractalstructuresandapreliminarydiscussionontherelatiobetweenDandbvalueHat-KunJIANG(蒋海昆)andShou-ZhongDI...
简介:CumulativefrequencybvaluewithoutupperboundmagnitudeanditsregressiondeterminationJian-WenSHEN(沈建文)(SeismologicalBureauofAnhuiP...