th Oe em oe Toneer amgggspemey = age 56 Y Miyake, Y Sug:ira and K. Kameda Vol. V No temperature, 27.1 C, the chlorinit) 19 2594, and o,, 22.51 at 50m depth. oticr nand the water system 8B, o the southern side of the [ine had T. Cl. 4 34%, and «, 22 U9. hus, it seems tnat there was a slight but jurct in the propert.es between tw: witer systems, which might be one causes ¢f the branching 344 On the v7.0°C, definite of the Te radioactive water flowing on the main direction of the North Equatorial Currert extended Sooner towurd ‘le west than in the southern part where the ow rite was smaller because the jatter was near the boundary between the North Rg iater-al Current and the Eo carorttl Counter Current and there was also the op- pressier due to the nerth-eastward inclination of the Equatorial Counter Current. Tras oF the WNWdirection the activity of 100 cpm / reached as from Bekiri Atoll, wrile on the WoS‘\V direction the extension was It is te be neted that the radiooct:vity was also detected at the 80b xr: from Bikini on the ENE cbrection This is the end part of ifyocostsbution turn.ng *) far as 2000km ontiy T@00 km. position 700~ the radioactiv- the eat at about 250km north of Bikini Atoll Fig. 4 : clarify the cause of rhis turning on the backward direction of the North Ecuator al Current may ce oe of "he :..portant problems. MPoueh it is not clear at present, woether it was the extention of the easterly eurrert alorg the northery ‘eundacy of tae North Equatorial Current which was foind recently between “s0SR~ uO Woo. or ait was only the local eddy, several diseuss ons will be done velow on his point. Wher we inveStigate the horizontal distribution of water svstems near Bikini Avcll bh. using the Tes diiervacns of waters at the depth of 50m beiow the surface. weocan toad out that there ore atieast four different types uf waters Fig 4:. The first one Aus bighly salive water chlerimty 1934, water temperature, 27.5°C, go 2277 coveriag the areu northern than 1S°N I che southern part of che atell there is the second tyre of water C which belongs te the Equatoria, Gunter Current with smailer chiorimity C1, 18.9%) and hoagher temperature: TL 6 he turd one B belongs to the North Equatorial Current representing the . termed ate property between A and C. In the southern part of the water C. there extese tie water DY of tne South Equatorial Current with bhagher culormmity. Cl i+ 6% ond higher temperature T, 28.0°C.. The water Bomav bec lassite rt ta. sus-eroups B, and B, as mentioned avove. As shown on Fig. i the cast part of B was comparatively broad and it became narrower on approa.cing uo the west. it was probably due to that at the time the boundary between waters B and C somewhat inclined to the north. Therefore, the North Equatorial Current was pressed »y the Equatorial Counter Current and the backward current flowing toward the north-east direction of Bikini Atoll would have deen resiited. WNKG The observation of the curren’ direction obtained in stfu also suggests the preseme of counter or eddv current in the same area I[t is, however. not sure whether this current would form ‘he crgin of the general easterly current as mentioned above. ' On the other hand, a remarkable loop of the isochlor surface distribution of the chloririty -Fig. 5 lines shown in the in the northern area of Bikini also indicates the presence of eddv Rea As shown in Figs. 6 and 7. 1: the vertical distributions of phosphate and the dissolved «xygen along 15°N thee was the subsidence in the area near 15°N, “S40