High time resolution fluctuations in volcanic carbon dioxide degassing from Mount Etna

Abstract

We report here on the first record of carbon dioxide gas emission rates from a volcano, captured at ≈1Hz. These data were acquired with a novel technique, based on the integration of UV camera observations (to measure SO2 fluxes) and field portable gas analyser readings of plume CO2/SO2 ratios. Our measurements were performed at the North East crater of Mount Etna, southern Italy, and the data reveal strong variability in CO2 emissions over timescales of tens to hundreds of seconds, spanning two orders of magnitude. This carries important implications for attempts to constrain global volcanic CO2 release to the atmosphere, which are mostly based on spot measurements of individual targets, and may therefore be subject to error, by failing to average out this variation. A common oscillation in CO2 and SO2 emission rates in addition to the CO2/SO2 ratios was observed at periods of ≈89s. Our results are furthermore suggestive of an intriguing temporal lag between oscillations in CO2 emissi...