Fractal pattern in hydrothermal emission

The thermal spring Agnikunda, in eastern India, is characterized by spontaneous emission of helium bearing natural gases. Temporal variation of the concentration of this helium has been observed for a fairly long period of time and seen to be random in nature. This irregular variation of helium emanation with time has been studied by fractal statistics, Hurst's rescaled range analysis. The temporal variation of concentration of helium shows persistent behaviour with Hurst coefficient about 0.6. Various causes for the observed fractal nature of the temporal variation of helium is discussed in this paper.