Spring water and CO2 interaction at Popocatépetl volcano, Mexico

Abstract

Six years of monitoring HCO - and pH at selected springs at Popocatépetl during the present eruptive period are presented. Small peaks in HCO - concentration and P in springs are associated with small magmatic pulses at Popocatépetl volcano. The magma provides CO2-rich fluids into the water system controlled by meteoric recharge. The PCO2 in equilibrium with the springs is two to four orders of magnitude higher than air-saturated water. The high partial pressure of CO2 also suggests a direct interac- tion with the magmatic fluids. The isotopic signature of carbon as well, supports a magmatic origin for dissolved CO2.