1 Multi-year satellite observations of sulfur dioxide gas emissions and lava extrusion at Bagana volcano, Papua New Guinea B.T. McCormick Kilbride 1;∗, K. Mulina 2, G. Wadge 3, R.W. Johnson 4, I. Itikarai 2, and M. Edmonds 1 1COMET, Department of Earth Sciences, University of Cambridge, Cambridge, UK. 2Rabaul Volcanological Observatory, Rabaul, Papua New Guinea. 3COMET, Department of Meteorology, University of Reading, Reading, UK. 4School of Asia and the Pacific, Australian National University, Canberra, Australia. Correspondence*: Brendan T. McCormick Kilbride, Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, UK
[email protected] 2 ABSTRACT 3 Bagana, arguably the most active volcano in Papua New Guinea, has been in a state of 4 near-continuous eruption for over 150 years, with activity dominated by sluggish extrusion of 5 thick blocky lava flows. If current extrusion rates are representative, the entire edifice may have 6 been constructed in only 300-500 years. Bagana exhibits a remarkably high gas flux to the 7 atmosphere, with persistent sulfur dioxide (SO2) emissions of several thousand tonnes per day. 8 This combination of apparent youth and high outgassing fluxes is considered unusual among 9 persistently active volcanoes worldwide. We have used satellite observations of SO2 emissions 10 and thermal infrared radiant flux to explore the coupling of lava extrusion and gas emission 11 at Bagana. The highest gas emissions (up to 10 kt/day) occur during co-extrusive intervals, 12 suggesting a degree of coupling between lava and gas, but gas emissions remain relatively high 13 (∼2500 t/d) during inter-eruptive pauses.