Rates of volcanic CO2 degassing from airborne determinations of SO2 Emission rates and plume CO2/SO2: test study at Pu′u ′O′o Cone, Kilauea Volcano, Hawaii

Abstract

We present an airborne method that eliminates or minimizes several disadvantages of the customary plume cross‐section sampling method for determining volcanic CO2 emission rates. A LI‐COR CO2 analyzer system (LICOR), a Fourier transform infrared spectrometer system (FTIR), and a correlation spectrometer (COSPEC) were used to constrain the plume CO2/SO2 and the SO2 emission rate. The method yielded a CO2 emission rate of 300 td−1 (metric tons per day) for Pu′u ′O′o cone, Kilauea volcano, on 19 September 1995. The CO2/SO2 of 0.20 determined from airborne LICOR and FTIR plume measurements agreed with the CO2/SO2 of 204 ground‐based samples collected from vents over a 14‐year period since the Pu′u ′O′o eruption began in January 1983.