Degassing catastrophic

Fanale, F. P. (1971) A case for catastrophic early degassing of the Earth. Chem. Geol., 8, 79-105. 

At the same time, the conclusion concerning the catastrophic early degassing of the Earth and early formation of an ocean whose volume was still limited in the Early Precambrian, can hardly be extended automatically to other volatiles, in particular CO2, sulfur, and probably, HCl. 

A value of (" °Ar/3 Ar)i n = 520 is calculated from Equation (4) for the mantle. Once higher values were measured in MORE samples, such a simple formulation no longer appeared valid. Higher ratios can be obtained if an early catastrophic degassing event occurred, removing a fraction / of the ° Ar from the mantle into the atmosphere (Ozima, 1973). In this case, the term (1 —/) Arijio can be substituted for Ar o (see Ozima and Podosek, 1983). Then for a mantle with °Ar/3 Ar = 4 X lO" (see Section 4.11.2.4),... 

B. Ivanov, F. Langenhorst, A. Deutseh, and U. Homemann, How strong was impact-induced CO2 degassing in the K/T event Numerieal modelling of laboratory experiments, in Catastrophic Events Mass Extinctions Impacts and Beyond, (eds. C. Koeberl and K.G. MacLeod), Geol. Soc. Amer. Spec. Paper, (2001) in press. 

This simple calculation shows that the volume of hydrogen is out of proportion with the intensity of corrosion. It illustrates the hazard resulting from a closed tank in which corrosion takes place hydrogen will form, and any intervention such as welding without prior degassing can have catastrophic consequences. This type of accident may occur, for instance, when repairing ballast tanks of vessels. This applies, by the way, to any metal steel, aluminium, etc. 

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