NewZealandjusthadatasteofa"regional-source"tsunami-andonethatcouldhaveeasilybeenmuchmorethreatening,underdifferentcircumstances.

At8.28amthismorning,nearRaoulIsland,somekmawayfromNewZealand,an8.1quakeeruptedattheinterfaceoftheAustralianandPacificplates.

TidalsurgeassociatedwiththeeffectsofatsunamiwasobservedatTokomaruBayontheEastCapetoday.Photo/ClaudiaWaaka

ThejoltwasbigenoughtoknockoutthetidalgaugeonRaoulIsland,whichhadntexperiencedashakemeasuringlargerthan8.0in43years.

The.2quakewasalsoprecededbyaslightlysmaller,butstilllarge,7.8event.

WhiletodaysquakewouldhavecausedseriousshakingonRaoulIsland,onthewaterneartheepicentre,theresultingtsunamiwouldhavebeenbarelynoticeable.

"Itwouldhavebeenintheorderoftensofcentimetres,"saidDrJoseBorrero,ofRaglan-basedmarineconsultancyeCoastLtd.

"Butoveraspaceofhundredsofkilometres,ifyouresittingonaboatintheocean,youmightfeelsomeshockwaves