Table 6.1 Estimated relative input of metals and metalloids to the ocean from the atmosphere, compared to other sources. Also listed are the range and average concentrations for open ocean waters, the estimated residence time of each metal in the global ocean, and the major dissolved inorganic species in solution. Data taken from the literature [1 ]. Element %Pluvial Input to the Ocean* Ocean Conc Range (nm) Average Conc (nm) Residence time 10 yrs Major dissolved inorganic species in seawater Al 8 0. 40 0 0.6 x Al( OH) x, x =, 4 V 16 0 40 0 45 HVO 4 Cr 5 4 8. CrO 4 Mn 16 0.08 5 0. 1. Mn + Fe 5 0.01 0.5 0.05 x Fe( OH) x, x =, Co 4 <0.01 0. 0.0 0.4 Co + Ni 4 1 8 8. Ni + Cu 14 0.5 4.5 4 0.97 0 CuCO Zn 1 0.05 9 5 0.51 Zn + As 0 5 9 HAsO 4 Mo 6 105 80 MoO 4 Ag 8 <0.01 0.04 0.0 0.5 1 x AgCl x, x = 1 4 Cd 45 <0.01 1 0.5 x CdCl x, x = 1 4 Hg 81 <0.01 0.00 0.56 x HgCl x, x = 1 4 Pb 6 <0.01 0.15 0.1 0.81 0 PbCO Ga 0.01 0.0 0. 9 Ga(OH) 4 Se 0.5. 1.7 6 SeO 4 Sb 1. 5.7 SbO 6 W 0.06 500 WO 4 U 14 500 UO 4 *Estimates of percentage are the fraction of the total flux. Table 6. Radioisotopes and their uses. Unless otherwise noted the isotopes are formed through the decay of the various uranium isotopes and their products. Data taken from various sources [, 16, 0]. Isotope Half-life Comment 4 Th 4.1 d Widely used to estimate vertical particulate transport: export production 0 Th 75,400 yr Used for long timescales: deep ocean sedimentation rates and distribution 8 Th 1.91 yr Used as a particulate tracer: colloidal aggregation 1 Pa,500 yr Used for long timescales: deep ocean sedimentation rates and scavenging 8 Ra 5.75 yr Diffuses from sediments, useful tracer of advection, vertical mixing 6 Ra 1599 yr Used to estimate advection of water masses: groundwater inputs 10 Pb. yr Used to estimate sedimentation rates Rn.8 d Used to estimate upper ocean mixing: gas exchange 14 C 570 yr Cosmogenic and bomb-produced: used over long timescales 7 Be 5 d Cosmogenic: used to estimate bioturbation, mixing and recent sedimentation 17 Cs 0. yr Bomb-produced: used as a specific age marker ( 196) for sediments
Table 6. Equilibrium (binding) constants for metal-sulfide clusters of a variety of metals. Taken from [47]. Reprinted with kind permission from Springer Science+Business Media. Metal complex Ag Metal complex Cu Pb Zn M 6 S 78. M S 54.7 6.9 48.5 M 8 S 4 106. M 4 S 4 M 4 S 6 96.4 84.4 Table 6.4 Typical concentration ranges for metals in nearshore and offshore sediments. All values are given in nmol g 1 dry weight of sediment. Data obtained from a variety of sources. Element Highly Contaminated Urban Influenced Remote Estuarine/Coastal Deep Ocean Cr >.0 0.1 0. 0.01 0.07 0. Co >1.0 0.1 0.5 0. 1.0 0.1 Ni >.0 0.01 1.0 0.6 1.0 0.5 5 Cu >.0 0..0 0. 0.9 0.5 9 Zn >0 0.05 10 0.05 1.0 0.05 1 Cd >1.0 0.1 1.0 <0.01 0.01 0.0 Hg >0.05 0.01 0.05 <0.01 0.001 0.01 Pb >.5 0.1 1.0 0.01 0.1 0.0 0.5 Ag >0.0 0.001 0.01 <0.01 <0.01 Sn >0.1 0.01 0.1 <0.01 <0.0 As >.0 0.5 1.0 <0. 0. Se >0.05 0.005 0.01 <0.01 <0.01 Table 6.5 The range and average concentration for the fraction of the metal in the truly dissolved phase for filtered water from San Francisco Bay. Data from [9]. Metal Fe (μm) Mn (μm) V (nm) Cr (nm) Co (nm) Cu (nm) Zn (nm) Cd (nm) Pb (nm) Ag (pm) Truly Dissolved <0.09 <0.0 6..0.4 1. 119 <0.1 <0.01 <1 Minimum Maximum 40 0.8 91 7 9 0 60 1. 0.8 15 Average 5.1 46 5 11 11 4. 4 0.6 0.09 5.1
Table 6.6 Reactions included in the model of Van Cappellen and Wang [17] for the oxic and anoxic degradation of organic matter (Reactions A 1 to A 6) and inorganic redox reactions. Reprinted with permission from Taylor & Francis. Irreversible Reactions (A 1 to A 19) and Alkalinity Conservation (A 0. Reactions A 1 to A 6 represent the net degradation of organic matter deposited from the water column. Reactions A 7 to A 16 describe the reoxidation of secondary species produced during the oxidation of organic matter. Reactions A 17 to A 19 correspond to the non-reductive precipitation of carbonate and sulfide mineral phases. The irreversible production or consumption of protons is buffered by the dissolved carbonate/sulfide acid-base interconversions (A 0). ( CH O) ( NH ) ( H PO ) + ( x + y) O + ( y + z) HCO x y 4 z R1 ( x + y + z) CO + yno + zhpo + ( x + y + z) H O 4 4 ( CHO) x( NH ) y( HPO 4 ) z + x + y NO 5 R x + 4y N x y + 10z x y z 5 + CO HCO + 4 + 10 5 5 x + 6y + 10 + zhpo z 4 + H O 5 ( CH O) ( NH ) ( H PO ) + xmno + ( x + y z) CO + ( x + y z) H O x y 4 z R xmn + ( 4x + y z) HCO + ynh + HPO + + 4 4 R ( CHO) x( NH ) y( HPO 4 ) z 4xFe( OH) ( 7x y z) CO 4 + + + + 4xFe A-4 + ( 8x + y z) HCO + ynh + 4 + zhpo 4 + ( x y + z) HO x ( CHO) x( NH ) y( HPO 4 ) z SO + 4 + ( y z ) CO + ( y z ) H O A-5 R x 5 H + S + ( x + y z) HCO + ynh4 + zhpo 4 ( CHO) x( NH ) y( HPO 4 ) z + ( y z) HO R x x y 4z 6 CH 4 + + A-6 CO + ( y z) HCO + ynh + 4 + zhpo 4 + 1 R7 Mn + O + HCO MnO + CO + HO A-7 + 1 1 R8 Fe + O + HCO + HO Fe( OH) + CO 4 A-8 Fe + MnO 9 + HCO + H O R Fe( OH) + Mn + CO A-9 + NH O HCO R 10 + + NO + CO + H O A-10 4 A-1 A- A- H S O HCO R11 + + SO + CO + H O 4 R o H S + CO + MnO 1 Mn + S + HCO + A-11 A-1 R o H S 4CO Fe OH 1 + + + ( ) Fe + S + 4HCO + H O A-1 FeS O R 14 + + Fe + SO A-14 4 CH O R 15 + CO + H O A-15 4 R16 CH + CO + SO HCO + H S 4 4 A-16 R17 Mn + HCO MnCO + CO + H O + R18 Fe + HCO FeCO + CO + H O A-18 + R19 Fe + HCO + H S FeS + CO + H O A-19 CO + δco + δh O + ( 1 δ) H S ( 1+ δ) HCO + ( 1 δ) HS 0 δ 1 A-0 A-17
Table 6.7 Depth integrated rates of carbon remineralization for different marine and freshwater environments and the fraction of degradation by each process (Reactions A 1 to A 6 in Table 6.6). Taken from [17]. Reprinted with permission from Taylor & Francis. Process Deep Sea Shelf Coastal Estuarine Oligotrophic Lake Eutrophic Lake Corg oxidation 7 79 981 8 759 % via oxic respiration 80 6.0 4. 48.0 % via nitrate reduction 11 5.8 1.6 9.9 9. % via metal reduction.5 <1.5 0.4 0.4 % via sulfate reduction 6 87 91 4.7 0 % via methanogenesis 0 0 0 7 87 Table 6.8 Equilibrium constants used in the modeling of mercury partitioning in sediment porewater. Summarized from [108, 19], and references therein. Complex LogK Complex LogK Dissolved HgOH + 10.7 HOHgSH 40.5 Hg(OH). Hg(SH) 7.7 Hg( OH) 0.9 HgS H 1.5 HgCl + 7. HgS. HgCl 14.0 HgS x 11.7 HgCl 15.1 Hg(SR) 4 HgCl 4 15.4 HgOHCl 18.1 Solid Solid RFeSHg + 5.1 Hg(SR) 4 RFeS -Hg f(crs)* Notes: # Solid thiol content was estimated using literature information for the fraction of organic matter that is reduced, and the fraction of reduced S as thiol; a ratio of RSH/total OS of 0.06. *The relationship between Hg incorporation and pyrite content was estimated based on data for the degree of trace metal pyritization. The following relationship was derived: DTMP-Hg = 0.157ln(CRS) + 0.48.
Table 6.9 Compiled average data for different types of deep ocean sediments showing the contrasting concentrations of both major and minor elements. Concentrations given either as a percent value (%mass/mass) or as μmol kg 1. Summarized from [84] and converted to molar units where appropriate. Element Pelagic Clay Fe/Mn Nodule Basal Sediment Ridge Element Pelagic Clay Fe/Mn Nodule Basal Sediment Ridge Al 8.40%.70%.74% 0.50% Y 449.9 1687. 149.8 As 67.0 1869. 195.9 Zr 164.9 61.6 464.4 Bi.5.5 0.8 Nb 150.7 58. 54.9 Cd.7 89.0.6 5.6 Pd 0.1 0.1 0. Co 156.4 45,840.4 19. 178.7 La 0.4 110. 705.5 08.8 Cr 170.8 67.1 88.5 1057.7 Hf.0 44.8 9.0 Cu 97.0 70,866.1 1,440.9 11,496.1 Ta 5.5 55. 11.6 Fe 6.50% 1.50% 0% 18% W 1.8 544.1 Ga 86.9 9.7 6.0 Re 0.00 0.005 Ge.0 7.4 0.6 Os 0.07 0.01 Hg 0.5 1.4.7 Ir 0.00 0.04 0.0 Mn 0.67% 19% 6% 6% Pt 0.0 1.0 Mo 81.5 4171.0 0.0 1.8 Ag 1.0 0.8 1.7 57.5 Ni 918. 11,46.1 786.5 75.4 Au 0.0 0.0 0. Pb 86.1 44.6 48.6 7.6 Lanthanides Sb 8. 8.4 19.6 Ce 70.9 78.0 4.7 60.0 Sc 4.6.4 Pr 71.0 55.5 17.0 0.0 Se.5 7.6.9 Nd 98. 1095.7 60. 159.5 Sn.7 16.8 5.1 Pm Th 56.0 19. 10. Sm 55.5 199.5 1.7. Ti,504.9,778.9 1174. Eu 1. 59. 5.5 9.9 U 10.9 1.0 17.6 9.4 Gd 5.8 0.4 14.7 8.1 V 57.6 98. 8840.9 Tb 8.9 4.0 0.0 0.0 Zn 599.4 18,48.6 7186.5 5810.4 Dy 45.5 190.8 17.4 44.9 Group I and II Ho 9.1 4.4 8.5 0.0 Li 81. 11,57.4 18,011.5 Er 4.5 107.6 77.1.5 B 1,96. 7,777.8 11,88.9 46,96. Tm.4 1.6 0.0 0.0 Be 88.6 77.5 74.6 Yb.1 1156 75.1.9 Rb 186.5 198.8 187.1 Lu.1 10. 1.6 5.0 Cs 45.1 7.5 0.0 Sr 054.8 9474.9 4006.8 Ba 16,751.6 16,751.6 45,75.1 4,699.9 Table 6.10 Concentrations of various metals in manganese nodules and related materials compared to those found in pelagic clay and average shale. Data taken from [168, 169]. Element Average Shale Pelagic Clay Mn Nodules Mn Crusts (Co Rich) Baltic Fe/Mn Concretions Hydrothermal Crusts % Mn 0.05 0.4 17 0 8 8.7 9 54 % Fe 5. 5.4 7 14 17 10 0.07 % Co <0.001 0.011 0.09 0.44 0.67 1. 0.01 % Ni 0.00 0.01 0. 1.4 0.4 0.50 <0.01 0.08 0.0 % Cu 0.005 0.0 0.17 1. 0.0 0.10 <0.01 0.0 Mn/Fe 0.01 0.08 0.7 5.4 1..0 0.4.9 774
Table 6.11 The major trace elements and isotopes that will be included in the Geotracers program studies. Those indicated in italics are not considered key parameters but are likely to be measured on cruises. Data taken from the GEOTRACERS Science Plan [188]. Parameter Key uses Fe Al Zn Mn Cd Cu Co Hg, Pb, Ag, Sn δ 15 N NO ( ) Tracer of atmospheric inputs (mineral dust) Tracer of Fe input; redox cycling, margin inputs ; paleoproxy for nutrient Anthropogenic source indicators Modern and paleoproxy δ 1 C Modern and paleoproxy for nutrients and circulation 0 Th Flux of particles, scavenging and ocean circulation 1 Pa Paleoproxy of circulation and productivity; particle tracer Pb isotopes Tracer of natural and anthropogenic inputs 10 Pb Source tracer Nd, Hf isotopes Tracer of natural sources to the ocean Ra isotopes Indicators of groundwater discharge (coastal waters) He Hydrothermal inputs Metal stable isotopes Paleoproxy; redox, chemical and biological processes O isotopes Nutrient paleoproxy Other U-series isotopes Particle processes, inputs and removal processes Table 6.1 Estimated fluxes of metals into the deep ocean as reported in [1], and taken from references therein. Data converted to molar units. Metal Part. Conc. (mmol kg 1 ) Flux (μmol/m /yr) Min. Max. Min. Max. Al 685 1780 0,00,450 Fe 160 40 1960 8500 Mn 7. 0 100 65 Ni 0.4 1.0 6..0 Co 0.09 0.17 1.9.7.0 V 0.8 1.4 7. 9.0 Cu 0.5 1.6 5.7.0 Pb 0.1 0.5 1. 9.0 Zn 1.1.0 15 44 Cd 0.004 0.009 0.0