Abstract
The deep ocean water obtained by pipe lines deployed at ca. 700 m depth o Hualien coast, eastern Taiwan has been characterized by its physical properties to be the result of mixing of
three far distance sources: (1) the Deep Arctic/Circumpolar Water (DACW), (2) the North Paci c
Intermediate Water (NPIW) which is originated from the sinking of the mixture of Okhotsk Sea
Water/Oyashio Water/Kuroshio Extension Water (OKW＋OYW＋KEW) and (3) the Kuroshio
Tropical Water (KTW). By calculating the mixing ratio, the contribution fractions of the three
end-members are approximately 34％, 59％ and 7％, respectively. If judging by water column type
at 27.0 σθ, the water shows 66％ and 34％ resemblance to the water of the Philippine Sea and the
South China Sea, respectively. The measurement of silicate content in the intake water (range 78‒ 92 μM Si at 700 m) is a convenient way to monitor the stability of the water layer as the resolution
can reach 0.04℃ μM－1. The risk of the radioactive pollution due to the 2011 Fukushima Nuclear
Event has been evaluated by analyzing the water mass movements along the isopycnal lines.