There is very little systematic data on volcanic emissions because of the lack of suitable monitoring equipment. The available data show a very significant correlation between volcanic activity and emissions. Therefore, there is a great need for new instrumentation that will provide the needed data to understand and model the role of geochemistry in volcanism. The proposed research is a collaboration between volcanologists and gas sensor specialists to develop and use advanced instrumentation for systematic monitoring of important volcanic gases (e.g., HC1, CO2, SO2, H2S, HF, H2O and temperature). Recent advances in microsensor technology and electronics will be exploited to develop a rugged, low power, low cost, field worthy monitoring system. The units would be designed to collect and transmit real-time emissions data for a period of six months without any manual intervention. The data acquired by the instrumentation is expected to stimulate the development of new models of volcanic behavior.