Pacific Ocean dissolution

Murray RW, Knowlton C, Leinen M, Mix AC, Polsky CH (2000) Export production and carbonate dissolution in the central equatorial Pacific Ocean over the past 1 Myr. Paleoceanography 15(6) 570-592... 

Figure 2.14. The log of dissolution rate in percent per day versus the log of (1-fi). A = whole Indian Ocean sediment dissolved in deep-sea sediment pore water B = whole Pacific Ocean sediment dissolved in Atlantic Ocean deep seawater C = whole Atlantic Ocean sediment dissolved in Long Island Sound seawater (Morse and Berner, 1972) D = > 62 pm size fraction of the Indian Ocean sediment dissolved in Atlantic Ocean deep seawater, E = the 125 to 500 pm size fraction of Pacific Ocean sediment dissolved in Atlantic Ocean deep seawater F = 150 to 500 pm Foraminifera dissolved in the Pacific Ocean water column. (After Morse, 1978.)...

Betzer et al. (1984, 1986) studied the sedimentation of pteropods and foraminifera in the North Pacific. Their sediment trap results confirmed that considerable dissolution of pteropods was taking place in the water column. They calculated that approximately 90% of the aragonite flux was remineralized in the upper 2.2 km of the water column. Dissolution was estimated to be almost enough to balance the alkalinity budget for the intermediate water maximum of the Pacific Ocean. It should be noted that the depth for total dissolution in the water column is considerably deeper than the aragonite compensation depth. This is probably due to the short residence time of pteropods in the water column because of their rapid rates of sinking. 

Byrne R.H., Acker J.G., Betzer P.R., Feely R.A. and Cates M.H. (1984) Water column dissolution of aragonite in the Pacific Ocean. Nature 312,321-326. 

Open Ocean Dissolution Experiments. The first direct studies of calcium carbonate dissolution in deep seawater were made by Peterson (41) and Berger (42). Peterson suspended spheres of Iceland spar calcite, held in pronged plastic containers, at various depths in the Central Pacific Ocean for four months. The amount of dissolution was determined by weight loss, which was small relative to the total weight of the spheres. On the same mooring Berger suspended sample chambers, which consisted of... 

Figure 11. Plot of the Peterson (41) and Berger (42) results for their water-column dissolution experiments in the Central Pacific Ocean, and the Morse and Berner (45) laboratory experiments as a function of equivalent depth. The depth of the lysocline was calculated from the data of Bramlette (49) (after Bef. 45).

Figure 15. The measured rate of dissolution (Rm) per gram of calcium carbonate, divided by the initial rate of dissolution (Rr) vs. the percent of the calcium carbonate which has dissolved. Runs were carried at Q = 0.40.1.O.S. = Indian Ocean sediment, P.O.S. = Pacific Ocean sediment (after Ref. 30).

Figure 17. Log of the dissolution rate vs. total carbonate ion concentration for synthetic aragonite, pteropods, calcitic Pacific Ocean sediment, and foraminifera in the 125-500 iim size fraction. (A) indicates ihe aragonite equilibrium total carbonate ion concentration at 25°C, 1 atm (26). (C) indicates the calcite equilibrium total carbonate ion concentration at 25°C, 1 atm (25).

Figure 18. Ratio of measured rates of dissolution per gram to the initial dissolution for pteropods and calcite Pacific Ocean sediment (57)...

Shackleton N. J. (1977) Tropical rainforest history and the equatorial Pacific carbonate dissolution cycles. In Fate of Fossil Fuel CO2 in the Oceans (eds. N. R. Anderson and A. Malahoff). Plenum, NY, pp. 401-427. 

Figure 2 Rate of carbonate dissolution from deep-sea sediment versus (1 — O). SoUd Une from Hales and Emerson (1996), dotted line from Keir (1980), dashed line from Atlantic Ocean, and dotted and dashed line from Pacific Ocean sediment results of Morse (1978). Note that Hales and Emerson (1996) used a different calcite solubility product.

On time scales of oceanic circulation (1000 y and less) the internal distribution of carbonate system parameters is modified primarily by biological processes. Gross sections of the distribution of Aj and DIG in the world s oceans (Fig. 4.4) and scatter plots of the data for these quantities as a function of depth in the different ocean basins (Fig. 4.5) indicate that the concentrations increase in deep waters (1-4 Ion) from the North Atlantic to the Antarctic and into the Indian and Pacific Oceans following the conveyer belt circulation (Fig. 1.12). Degradation of organic matter (OM) and dissolution of GaGOs cause these increases in the deep waters. The chemical character of the particulate material that degrades and dissolves determines the ratio of At to DIG. 

They suggested that most of the carbonate dissolution in the deep ocean (Fig. 9.5) occurs within the sediments (85 %). The extension of their results from Pacific and Indian Ocean to the Atlantic Ocean leading to 120 10 molyr of global dissolved carbon fluxes from sediments may, however, be critical because of the completely different deep-water conditions in the Indo-Pacific and the Atlantic. Deep ocean waters in the Indian and Pacific Oceans are known to be much older and depleted in CO implying that a much higher proportion of calcite dissolution contributes to the total alkalinity input there. However, despite this problem of different bottom-... 

Murray RW, Leinen M, Isem AR (1993) Biogenic flux of A1 in the central equatorial Pacific Ocean Evidence for increased productivity during glacial periods. Paleoceanogr 8 651-670 Murray RW, Knowlton C, Leinen M, Mix AC, Polski CH (2000) Export production and carbonate dissolution in the central equatorial Pacific Ocean over the past 1 Ma. Paleoceanogr 15 570-592 Nancollas GH, Amjad Z, Koutsoukas P (1979) Calcium phosphates-speciation, solubility, and kinetic considerations. Am Chem Soc Symp Ser 93 475-497... 

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