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

We report here on thefirst record of carbon dioxide gas emission rates from a volcano, captured at≈1 Hz. These
data were acquired with a novel technique, based on the integration of UV camera observations (to measure SO2
emission rates) and field portable gas analyser readings of plume CO2/SO2 ratios. Our measurements were
performedat 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
importantimplications for attempts to constrain global volcanic CO2 release to the atmosphere, and will lead to
an increased insight into short term CO2 degassing trends. A common oscillation in CO2 and SO2 emission rates
in addition to the CO2/SO2 ratios was observed at periods of ≈89 s. Our results are furthermore suggestive of
an intriguing temporal lag between oscillations in CO2 emissions and seismicity at periods of ≈300–400 s,
with peaks and troughs in the former series leading those in the latter by ≈150 s. This work opens the way to
the acquisition of further datasets with this methodology across a range of basaltic systems to better our
understandingof deep magmatic processes and of degassing links to manifest geophysical signals