Oftheworld'soceans,thePacifichasthemostabundantdistributionofseamounttrails,oceanicplateausandhotspots,andhasthelongestfracturezones.However,littleisknownoftheirthermalstructuresduetodifficultiesofheatflowmeasurementandinterpretation,andininferringthermalanomaliesfromlow-resolutionseismicvelocities.Usingrecentlypublishedglobalmagneticmodels,wepresentthefirstindependentconstraintonPacificgeothermalstateandmantledynamics,byapplyingafractalmagnetizationinversionmodeltomagneticanomalydata.Warmthermalanomaliesareinferredforallknownactivehotspots,mostseamounttrails,somemajorfracturezones,andoceaniclithospherebetween~100and~140Mainage.WhilemostCuriepointsareamongtheshallowestinthezoneroughlyboundedbythe20Maisochrons,abnormallydeepCuriepointsarefoundalongnearlyallridgecrestsinthePacific,relatedtopatchy,long-wavelengthandlarge-amplitudemagneticanomaliesthataremostlikelycausedbyprevailingmagmaticorhydrothermalprocesses.ManylargecontrastsinthethermalevolutionbetweenthePacificandNorthAtlanticsupportmuchstrongerhydrothermalcirculationoccurringinPacificlithospheresyoungerthan~60Ma,whichmayhavedisguisedfromsurfaceheatflowanydeepthermalsignaturesofvolcanicstructures.Yet,atdepthsoftheCuriepoints,ourmodelarguesforwarmerPacificlithosphereforcrustalagesolderthan~15Ma,givenaslightlyhigherspatialcorrelationofmagnetizationinthePacificthanintheNorthAtlantic.
