Measured carbon dioxide emissions from Oldoinyo Lengai and the skewed distribution of passive volcanic fluxes

Airborne measurements of CO ₂ released from Oldoinyo Lengai, the only carbonatite-erupting volcano in the world, reveal a CO ₂ flux of 0.055 × 10 ¹² mol/yr. This flux is substantially smaller than that of Mount Etna. It is proposed and that the subaerial flux distribution may be a power-law distribution (fractal) rather than Gaussian. Although rigorous testing of the power-law nature of the flux distribution is impossible, the skewed nature of the distribution and low value of the power-law exponent suggest that simultaneous measurement of the 20 largest-flux volcanoes could yield an accurate assessment of the volcanic CO ₂ flux. Normalizing the emission flux by scaling per unit crater area to investigate the extension of the power-law behavior to geothermal areas with lower gas fluxes yields a power-law exponent of ~1 and predicts a subaerial volcanic-metamorphic CO ₂ flux of 6 × 10 ¹² mol/yr. -from Authors