摘要
Verticalprofilesfortheuranium-seriesradioisotopes210Pband210Powereobtainedatthetwohydrothermalventsites,theIheyaRidgeandtheMinami-EnseiKnoll,intheMid-OkinawaTroughin1993and1994,respectively.In1995,bothradioisotopesweremeasuredattheMinami-EnseiKnollagain.AttheIheyaRidge,wherethehydrothermalactivityisnotactiveasreflectedbytheCH4and222Rndata,boththetotal210Pband210Poactivitiesshowdeficiencyrelativetotheirparents,andthemeanresidencetimeof210Pband210Poisapproximatelyequalto20and2～5a,respectively.AttheMinami-EnseiKnoll,whichischaracterizedbyblacksmokers,thetotal210Pb(0.167×10-3～2.5×10-3Bq/kg)aroundtheplumesisdeficientrelativeto226Rabutthetotal210Poactivities(1.83×10-3～2.83×10-3Bq/kg)areinexcessrelativeto210Pb.The210PoactivitiesarehigherthanthoseintheEastChinaSeaandtheOkinawaTroughandexcess210Pohasbeenfound.The210Pb/226Raand210Po/210Pbactivityratiosare0.1～0.4and1.1～7.8,respectively.210Pbispreferentiallyscavengedinthehydrothermalplumes.Thepossiblemechanismsgoverningtheconcentrationof210PbintheMinami-EnseiKnollinvolvealateraltransportof210Pbviadiffusion.Thehigh210Po/210Pbactivityratiosinthehydrothermalplumessuggestadepletionof210Pbandadditionof210Pointhehydrothermalventarea.
出版日期
2002年01月11日（中国Betway体育网页登陆平台首次上网日期，不代表论文的发表时间）
