107
Minor Elements in Seawater
The resuspension and flux of Al from the sediments leads to an increase in the
concentration in bottom waters.
5. Middepth maxima: A profile of this type can result from a hydrothermal input from
the midocean ridge system. The elements Mn 2+ and 3 He are good examples of this
type of profile (see Figure 3.22 and Figure 3.23). The fluxes of these elements from
hydrothermal plumes (Chapter 10) have been used to trace them in deep ocean waters.
Ni (nmol kg
–1 )
0 2 4 6 8 10 12
Depth (m)
0
1000
2000
3000
4000
5000
SiO 2 (µmol kg
–1 )
0
50
100 150 200
PO 4 (µmol kg
–1 )
0
1
2
3
4 0
1000
2000
3000
4000
5000
North
Atlantic
North
Atlantic
North
Atlantic
North
Pacific
North
Pacific
North
Pacific
Figure 3.11
Comparison of the profiles of nickel (Ni) to silicate (SiO 2 ) and phosphate (PO 4 ) in the Atlantic and Pacific Oceans.
Se (nmol kg
–1 )
0.0
0.4
0.8
1.2
1.6
Depth (m)
0
1000
2000
3000
4000
PO 4 (µmol kg
–1 )
0.0
1.0
2.0
3.0
4.0
0
1000
2000
3000
4000
Si (µmol kg
–1 )
0
50
100
150
200
Silica
Phosphate
Selenium
(IV)
Selenium
(VI)
Figure 3.12
Comparison of the profiles of selenium (Se) to silica (Si) and phosphate (PO 4 ) in the Pacific Ocean.