Ocean basins data

Table 1.6 Average relative concentrations [wt.%] of the principal clay mineral groups in the < 2 Dm carbonate-free fraction in sediments from the major ocean basins (data from Windom 1976).

Figure 6 The characteristic features of NPDW-normalized patterns of dissolved REEs in different oceanic basins. Data from Alibo and Nozaki (unpublished) and Nozaki etal. (1999).

Figure 3 Concentrations of dissolved Cd versus PO measured in seawater from a subset of the global dataset representing the major ocean basins. Data are from the same references in Figure 2...

Fig. 11-16 Partial pressure of CO2 in surface ocean water along the GEOSECS tracks (a) the Atlantic western basin data obtained between August 1972 and January 1973 (b) the central Pacific data along the 180° meridian from October 1973 to February 1974. The dashed line shows atmospheric CO2 for comparison. The equatorial areas of both oceans release CO2 to the atmosphere, whereas the northern North Atlantic is a strong sink for CO2. (Modified with permission from W. S. Broecker et al. (1979). Fate of fossil fuel carbon dioxide and the global carbon budget, Science 206,409 18, AAAS.)...

A survey of available Th data for the ocean basins demonstrated that the highest concentrations are found nearer to the coasts, and it was concluded that while eolian inputs likely dominated the budget in the open ocean and could account for increases near the coast, fluvial inputs may be more important in coastal regions. This implies that some a mechanism causes recycling of Th that has been removed to estuarine sediments (Huh et al. 1989). A study of an ice-covered region of the western Arctic Ocean found that significant amounts of °Th and Th were advected into the basin (Edmonds et al. 1998). Therefore, it appears that while long-lived Th isotopes are rapidly removed into estuarine sediments, transport into the ocean basins may continue. 

Plot of nitrate versus phosphate from all depths and from selected WOCE cruises in all ocean basins. Straight line represents the mean oceanic trend in the data, which has a slope of about 16 1. Source-. From Gruber, N. (2004). Carbon-Climate Interactions, NATO ASI Series, p. 102. 

Table 7.1 Summary of selected nitrogen (NOj", NO2, NH +, urea, dissolved free amino acids [DFAA], DON) uptake rates from the major ocean basins, and upwelling, coastal and estuarine systems using tracer techniques. Rates were converted to common units (nmol N L" using data provided in the original publication or using conversion factors specified in the footnotes... 

Figures 4-6 show the isotopic compositions of MORBs from spreading ridges in the three major ocean basins. Figures 4(b) and 5(a) also show isotope data for marine sediments, because these are derived from the upper continental crust and should roughly represent the isotopic composition of this crust. In general, the isotopic relationships between the continental and oceanic crust are just what is expected from the elemental parent-daughter relationships seen in Figure 3. The high Rb/Sr and low Sm/Nd and Lu/Hf ratios of continental materials relative to the residual mantle are reflected by high Sr/ Sr and low " Nd/ " Nd and Hf/ Hf ratios (not shown).

Figure 13 Primitive-mantle normalized La/Sm versus La for MORE from three Ocean basins. Numbers in parentheses refer to the number of samples from each ocean basin. Lanthanum concentrations vary by about two orders of magnitude La/Sm varies by more than one order of magnitude. Data were extracted from PETDB.

While most studies of seafloor hydrothermal systems have focused on the currently active plate boundary ( 0-1 Ma crust), pooled heat-flow data from throughout the world s ocean basins (Figure 1) indicate that convective heat loss from the oceanic lithosphere actually continues in crust from 0-65 Ma in age (Stein et al, 1995). Indeed, most recent estimates would indicate that hydrothermal circulation through this older (1-65 Ma) section, termed flank fluxes, may be responsible for some 70% or more of the total hydrothermal heat loss associated with spreading-plate boundaries—either in the form of warm (20-65 °C) altered seawater, or as cooler water, which is only much more subtly chemically altered (Mottl, 2003). 

Figure 6 (a)-(c) Vertical profiles of N0g/HP04 ratios in each of the three major ocean basins. The data were... 

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