Efficient release of bromine by super-eruptions

Abstract Bromine is a key halogen element in the quantification of volcanic volatiles, but analytical difficulties measuring its very low abundances have prevented progress understanding behavior and role emissions. We present new data set bromine, chlorine, fluorine concentrations melt inclusions matrix glasses for two rhyolitic super-eruptions from Toledo Valles calderas, New Mexico, USA. show that before eruption, Br Cl were efficiently partitioned gas-saturated magma into separate fluid phase, we calculate mass halogens phase. further demonstrate syn-eruptive degassing was negligible during super-eruptions, so main source emissions must been If phase erupted, large could severely impacted atmospheric chemistry upon eruption.