Abstract:

Recent eruptions on the Reykjanes Peninsula have provided a unique opportunity to study volcanic gas compositions using Fourier Transform Infrared (FTIR) spectroscopy. In this talk, I will review the evolution of volcanic gas over the past years, focusing on the major gases (H₂O, CO₂, SO₂) and measurements performed during the initial stages (first day or two) of each eruption. Gas emitted during the onset of the Fagradalsfjall 2021 eruption preserved the initial volatile load of mantle-derived magma, while subsequent eruptions exhibited significant CO₂ depletion, likely due to pre-eruptive outgassing in shallow crustal storage zones. These findings highlight the utility of volcanic gas analysis in understanding eruption dynamics and magma evolution. Moreover, the process of pre-eruptive CO₂ loss has significant implications for linking magma reservoir processes to geophysical signals, such as seismicity and deformation, as well as refining estimates of CO₂ emissions during basaltic fissure volcanism.

All are welcome.