Carbon oceanic sources

Distribution of warm- and cool-water shelf carbonate In the modern-day ocean. Source From Mackenzie, F. T, and A. Lerman (2006). Carbon in the Geobiosphere Earth s Outer Shett. Springer-Veriag, p. 283. 

The approximate distribution pattern of ocean sources and sinks of atmospheric C02 is known the tropical basins of the oceans are mostly sources of C02, and high-latitude basins are sinks of C02. The role of rivers is reduced mainly to the transport of carbon to the coastal zone of the World Ocean ( 1 GtCyr-1). 

Figure 6 Terrestrial and oceanic sources and sinks of carbon inferred from inverse calculations with an atmospheric transport model and spatial and temporal variations in CO2 concentrations. The net fluxes inferred over each region have been averaged into 7.5°-wide latitude strips (Ciais et al., 2000) (reproduced by permission of the Ecological Society of America from Bcol. Appl, 2000, 10, 1574-1589).

O.C. Zafiriou, S.A. Andrews, W. Wang. Concordant estimates of oceanic carbon monoxide source and sink processes in the Pacific yield a balanced global blue-water CO budget, Global Biogeochem. Cycles, in press. 

Manganese minerals are widely distributed oxides, silicates, and carbonates are the most common. The discovery of large quantities of manganese nodules on the floor of the oceans may become a source of manganese. These nodules contain about 24% manganese together with many other elements in lesser abundance. 

Owing to the stability of the uranyl carbonate complex, uranium is universally present in seawater at an average concentration of ca. 3.2/rgL with a daughter/parent activity ratio U) of 1.14. " In particulate matter and bottom sediments that are roughly 1 x 10 " years old, the ratio should approach unity (secular equilibrium). The principal source of dissolved uranium to the ocean is from physicochemical weathering on the continents and subsequent transport by rivers. Potentially significant oceanic U sinks include anoxic basins, organic rich sediments, phosphorites and oceanic basalts, metalliferous sediments, carbonate sediments, and saltwater marshes. " ... 

Under low-dose conditions, forest ecosystems act as sinks for atmospheric pollutants and in some instances as sources. As indicated in Chapter 7, the atmosphere, lithosphere, and oceans are involved in cycling carbon, nitrogen, oxygen, sulfur, and other elements through each subsystem with different time scales. Under low-dose conditions, forest and other biomass systems have been utilizing chemical compounds present in the atmosphere and releasing others to the atmosphere for thousands of years. Industrialization has increased the concentrations of NO2, SO2, and CO2 in the "clean background" atmosphere, and certain types of interactions with forest systems can be defined. 

Gas hydrates are an ice-like material which is constituted of methane molecules encaged in a cluster of water molecules and held together by hydrogen bonds. This material occurs in large underground deposits found beneath the ocean floor on continental margins and in places north of the arctic circle such as Siberia. It is estimated that gas hydrate deposits contain twice as much carbon as all other fossil fuels on earth. This source, if proven feasible for recovery, could be a future energy as well as chemical source for petrochemicals. 

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