Volcanism global emissions

Allard P. (1992) Global emissions of He-3 by subaerial volcanism. Geophys. Res. Lett. 19, 1479—1481. 

Graf H.-F., Feichter J., and Langmann B. (1997) Volcanic sulfur emissions estimates of source strength and its contribution to the global sulfate distribution. J. Geophys. Res. 102, 10727-10738. 

Once global ice cover was achieved, it is estimated to have lasted several million years, based on the amount of time required to accumulate 0.12 bar CO2 at modem rates of volcanic CO2 emission (Caldeira and Kasting, 1992). This must have placed extreme stress on... 

INTRODUCTION 1.1 The Global Mercury Cycle FUNDAMENTAL GEOCHEMISTRY. 2.1 Solid Earth Abundance and Distribution. 2.2 Isotopic Distributions. 2.3 Minable Deposits. 2.4 Occurrence of Mercury in Fossil Fuels SOURCES OF MERCURY TO THE ENVIRONMENT. 3.1 Volcanic Mercury Emissions... 

Estimates of global volcanic sulfur emissions are summarized in Table 6. We have chosen a value of 9 X 10 t S yr as representative of the recent estimates. Therefore, by applying the determined Hg/S ratio, a global mercury flux from subaerial volcanism is estimated to be 45 t yr or 0.23 Mmol annually. These average emissions are only 5% of the natural flux of 5 Mmol yr estimated by Mason et al. (1994). Thus, and under long-term mean conditions, other types of terrestrial volatilization processes for mercury would dominate. Given this conclusion, it is important to place additional constraints on the validity of the 45 t yr estimate for subaerial volcanic mercury emissions. 

Fitzgerald W. F. (1981) Volcanic mercury emissions and the global mercury cycle. Programs and Abstracts, Symposium on the Role of the Ocean in Atmospheric Chemistry. lAMAP 3rd Scientific Assembly, Hamburg, Germany. August 17-28, 134p. 

Volcanoes emit with the dust many metals Cd, Hg, Ni, Pb, Zn, Ca, Sb, As and Cr (Nriagu and Pacyna 1988) for Cd and Hg metals, volcanoes contribute 40-50 % to global emission and for the latter 20-40 %. Based on global emissions estimates (Nriagu 1989), the emission of heavy metals amounts to 2-50 kt yr b The total volcanic dust emission has been estimated between 25 and 300 Tg yr i (Peterson and Junge 1971, Jonas et al. 1995, Pueschel 1995). 

The river run-off (Tables 2.28 and 2.29) is about 0.46 10 g yr carbon and is much larger than the total wet deposited carbonate (0.13 10 g yr carbon). The global volcanic CO2 emission is uncertain and there is given a value (Table 2.41) of... 

Mercury is present in the atmosphere mainly due to volcanic emissions but also as a result of industrial pollution. The total amount of global emissions of mercury to the atmosphere are not accurately known at present, although there is evidence that the atmospheric concentration of mercury has increased by about 1% per year for the last 25 years. The volcanic emissions are very big, between 25 000 and 100 000 tonne/year. They are responsible for a base level of mercury concentration in the ground and water. Mercury from the atmosphere is enriched in the surface layers of the ground, where it forms complexes with humus. Rain water dissolves and transports humus to streams and lakes. Mercury is enriched in the top layers of the bottom sediments. 

The effect of volcanic gas on global sulfur cycle is important. S concentration of volcanic gas from island arc is smaller than CO2 concentration. CO2 concentration of hot spot volcanic gas is similar to that of island arc volcanic gas, but amount of volcanic gas emission from hot spot volcanic activity (e.g., Hawaii) is small (Table 5.3). S concentration of volcanic gas from mid-oceanic ridges is similar to C concentration. Emission of S and C by volcanic gas from mid-oceanic ridge is small because solubility of gas into magma is high under high pressure condition at deep sea depth (3,000-4,000 m). Sulfur in basalt transfers to hydrothermal solution... 

Sulfur dioxide Is formed primarily from the Industrial and domestic combustion of fossil fuels. On a global scale, man-made emissions of SOj are currently estimated to be 160-180 million tons per year. These emissions slightly exceed natural emissions, largely from volcanic sources. The northern hemisphere accounts for approximately 90% of the man-made emissions (13-14). Over the past few decades global SOj emissions have risen by approximately 4%/year corresponding to the Increase In world energy consumption. 

Bates et al. (1992) global total for volcanic emissions reapportioned as 1/3 continental and 2/3 marine. 

Cadmium (Cd) anode cells are at present manufactured based on nickel-cadmium, silver-cadmium, and mercury-cadmium couples. Thus wastewater streams from cadmium-based battery industries carry toxic metals cadmium, nickel, silver, and mercury, of which Cd is regarded the most hazardous. It is estimated that globally, manufacturing activities add about 3-10 times more Cd to the atmosphere than from natural resources such as forest fire and volcanic emissions. As a matter of fact, some studies have shown that NiCd batteries contribute almost 80% of cadmium to the environment,4,23 while the atmosphere is contaminated when cadmium is smelted and released as vapor into the atmosphere4 Consequently, terrestrial, aquatic, and atmospheric environments become contaminated with cadmium and remain reservoirs for human cadmium poisoning. 

The finding that the heterogeneous chemistry that occurs on polar stratospheric clouds also occurs in and on liquid solutions in the form of liquid aerosol particles and droplets in the atmosphere provided a key link in understanding the effects of volcanic eruptions on stratospheric ozone in both the polar regions and midlatitudes. As discussed herein, the liquid particles formed from volcanic emissions are typically 60-80 wt% H2S04-H20, and hence the chemistry discussed in the previous section can also occur in these particles (Hofmann and Solomon, 1989). We discuss briefly in this section the contribution of volcanic emissions to the chemistry of the stratosphere and to ozone depletion on a global scale. For a brief review of this area, see McCormick et al. (1995). 

Hamilton, V. E., Wyatt, M. B., McSween, H. Y. and Christensen, P. R. (2001) Analysis of terrestrial and Martian volcanic compositions using thermal emission spectroscopy 2. Application to Martian surface spectra from the Mars Global Surveyor thermal emission spectrometer. Journal of Geophysical Research, 106, 14,733-14,746. 

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