Premium
Water masses labeled with global fallout 137 Cs formed by subduction in the North Pacific
Author(s) -
Aoyama Michio,
Hirose Katsumi,
Nemoto Kazuhiro,
Takatsuki Yasushi,
Tsumune Daisuke
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl031964
Subject(s) - mode water , subarctic climate , subtropics , subduction , geology , longitude , range (aeronautics) , oceanography , water mass , antarctic intermediate water , latitude , north atlantic deep water , deep water , ocean gyre , paleontology , tectonics , materials science , geodesy , fishery , composite material , biology
We provide a first cross section of the 137 Cs concentration along 165°E longitude in the western North Pacific. The 137 Cs profile is characterized by several subsurface cores with high 137 Cs, including two 137 Cs concentration maxima at 20°N, one at 250 m ( σ θ ≈ 25.5) and one at 400–500 m ( σ θ ≈ 26.0) depths. The shallower maximum is in the density range of North Pacific Subtropical Mode Water (NPSTMW) and the deeper one is in the density range of Lighter Central Mode Water (LCMW). The main 137 Cs cores, therefore, were formed by movements of NPSTMW and LCMW in the interior ocean during the past four decades. The 137 Cs has been transported from subarctic region to subtropics and tropics as a result of subduction.