Geology Reference
In-Depth Information
Table 2 The residence time and speciation of some elements in the ocean
Concentration
(mol L
1
)
Residence time
(year)
Element
Principal species
Li
1
2.6
10
5
2.3
10
6
Li
B(OH)
3
, B(OH)
4
4.1
10
4
1.3
10
7
B
F
, MgF
1
6.8
10
5
5.2
10
5
F
Na
1
4.68
10
1
6.8
10
7
Na
Mg
21
5.32
10
2
1.2
10
7
Mg
Al(OH)
4
, Al(OH)
3
7.4
10
8
1.0
10
2
Al
7.1
10
5
1.8
10
4
Si
Si(OH)
4
2
10
6
HPO
4
2
,PO
4
3
, MgHPO
4
1.8
10
5
P
Cl
5.46
10
1
1
10
8
Cl
K
1
1.02
10
2
7
10
6
K
Ca
21
1.02
10
2
1
10
6
Ca
1.3
10
11
4
10
4
Sc
Sc(OH)
3
2
10
8
1.3
10
4
Ti
Ti(OH)
4
H
2
VO
4
, HVO
4
2
, NaHVO
2
5
10
8
8
10
4
V
CrO
4
2
, NaCrO
4
5.7
10
9
6
10
3
Cr
Mn
21
, MnCl
1
3.6
10
9
1
10
4
Mn
3.5
10
8
2
10
2
Fe
Fe(OH)
3
Co
21
, CoCO
3
, CoCl
1
8
10
10
3
10
4
Co
Ni
21
, NiCO
3
, NiCl
1
2.8
10
8
9
10
4
Ni
CuCO
3
, CuOH
1
,Cu
21
8
10
9
2
10
4
Cu
ZnOH
1
,Zn
21
, ZnCO
3
7.6
10
8
2
10
4
Zn
Br
8.4
10
4
1
10
8
Br
Sr
21
9.1
10
5
4
10
6
Sr
Ba
21
1.5
10
7
4
10
4
Ba
La
31
, LaCO
3
1
, LaCl
21
2
10
11
6
10
2
La
HgCl
4
2
1.5
10
10
8
10
4
Hg
PbCO
3
, Pb(CO
3
)
2
2
, PbCl
1
2
10
10
4
10
2
Pb
4
10
11
2
10
2
Th
Th(OH)
4
UO
2
(CO
3
)
2
4
1.4
10
8
3
10
6
U
Source: based on Brewer, 1975
7
and Bruland, 1983.
8
4.2.2 Dissolved Gases
4.2.2.1 Gas Solubility and Air-Sea Exchange Processes. The ocean
contains a vast array of dissolved gases. Some of the gases, such as Ar
and chlorofluorocarbons (CFCs), behave conservatively and can be
utilised as tracers for water mass movements and ventilation rates.
Equilibrium processes at the air-sea interface generally lead to satura-
tion, and the concentration then remains unchanged once the water
sinks. Thus, the gas concentration is characteristic of the lost contact
with the atmosphere. There are several important non-conservative
gases, which exhibit wide variations in concentration due to biological
activity. O
2
determines the redox potential in seawater and CO
2
buffers
