Características físico-químicas de las aguas de goteo en las "Galerías Altas" de la Cueva de Nerja (Málaga)incidencia de los procedimientos de medida

Resumen

The physical-chemical characteristics (temperature, pH and electrical conductivity) of the drip water in the "High Galleries" (non-touristic zone) of the Nerja Cave have been monitored along the 2000 year. The results obtained indicate that the values of temperature and electrical conductivity are higher than those found in the touristic area and the pH values are smaller. This trend is thought to be induced by spatial changes in the Pco2of the cave atmosphere which, in turn, must reflect the fluxes of visitors as well as by other effects (ventilation, etc.). The identified trend is opposite to the one stated in a previous study (1991-1993). The reason is supposed to be a consequence of the different time elapsed from the dripping to the the measurement of the physico-chemical variables in each study, being shorter in the present. The exposition of the water samples to the cave atmosphere induces the off-gasing of CO, and the precipitation of CaCOy thus decresing the electrical conductivity and increasing the pH. In addition, a general direct relationship beween the conductivity and the drip water flow has been shown