Basedonthedataofearthquakecentroidmomenttensor(CMT)solution,P-wavefirstmotionfocalmechanismsolutionanddeepholebreakouts,apresent-daytectonicstressmapforeasternAsiaregioniscompiled.Theorigi-nalstressdataaresmoothedforevery200km′200kmareabytakingtheaverageofallstressindicatorswithineachsub-region.Thestressmapshowsthespatialdistributionoftheorientationofprincipalstressaxesandthestressregimes.AnearthquakefocalmechanismmapfortheeasternAsiaisalsogiven.Themapsoforientationofprincipalstressaxesshowthat,apartfromthestronginfluenceofthecollisionbetweentheIndianOceanplateandEurasianplate,thepresent-daytectonicstressineasternAsiaissignificantlyaffectedbytheback-arcextensionofthesubductionzones.ThejointeffectofthecontinentalcollisionattheHimalayaarcandback-arcextensionintheBurmaarcregionmayberesponsiblefortheremarkablerotationoftheprincipalstressorientationsinsoutheasternpartoftheTibetplateau.ThejointactionofthecollisionbetweenthePhilippineSeaplateandEurasianplateatTaiwanIslandandtheback-arcextensionoftheRyukyuarcaffectthestressfieldineasternpartofChina.Therearenostrongearthquakesinthepresentdayinthevastback-arcregionoftheJavatrenchsubductionzone.Theback-arcextensiontheremaycreateaconditionfavorabletothesouthwardflowofthelithospherematerialinsoutheasternAsia.IntheinnerpartoftheTibetplateauregion,roughlydemarcatedbytheKunlunmountain,thenorthernandnortheasternpartisabroadintracontinentalcompressivezone,whilethesouthernandsouthwesternpartisgenerallyinanormal-faultingstressstate.
