简介：IntheprocessofsolvingEulervectorsbasedonGNSShorizontalmovementfield,thenumberofestimatedparameterscanaffectEulervectorresults.Thisissueisanalyzedthroughtheoreticaldeductionandpracticalexampleinthispaper.Firstly,thedifferencebetweentheresultsofEulervectorsindifferentsolvingmodelsisdeduced.Meanwhile,basedonGNSShorizontalmovementfieldintheChinesemainlandfrom2004to2007,twocommonmodels(RRMandREHSM)areusedtodiscusstheimpactofsolvingmodelsonEulervectorsandthefollow-upstudy.Theresultshowsthatthemaximumvalueofthedifferenceinablock’sentirerotationcanreach2.6mm/a,andshouldnotbeignored.Therefore,theresultsofhorizontalmovementaredifferentusingdifferentkinematicblockmodels,andthisshouldbepaidmoreattentionintheanalysisofcrustalhorizontalmovement.

简介：Inthispaper,weproposeanearlyanalyticexponentialtimedifference(NETD)methodforsolvingthe2Dacousticandelasticwaveequations.Inthismethod,weusethenearlyanalyticdiscreteoperatortoapproximatethehigh-orderspatialdifferentialoperatorsandtransformtheseismicwaveequationsintosemi-discreteordinarydifferentialequations(ODEs).Then,theconvertedODEsystemissolvedbytheexponentialtimedifference(ETD)method.WeinvestigatethepropertiesofNETDindetail,includingthestabilityconditionfor1-Dand2-Dcases,thetheoreticalandrelativeerrors,thenumericaldispersionrelationforthe2-Dacousticcase,andthecomputationalefficiency.Inordertofurthervalidatethemethod,weapplyittosimulatingacoustic/elasticwavepropagationinmultilayermodelswhichhavestrongcontrastsandcomplexheterogeneousmedia,e.g.,theSEGmodelandtheMarmousimodel.Fromourtheoreticalanalysesandnumericalresults,theNETDcansuppressnumericaldispersioneffectivelybyusingthedisplacementandgradienttoapproximatethehigh-orderspatialderivatives.Inaddition,becauseNETDisbasedonthestructureoftheLiegroupmethodwhichpreservesthequantitativepropertiesofdifferentialequations,itcanachievemoreaccurateresultsthantheclassicalmethods.