Satellite-based constraints on explosive SO2 release from Soufrière Hills Volcano, Montserrat

Numerous episodes of explosive degassing have punctuated the 1995–2009 eruption of Soufrière Hills volcano (SHV), Montserrat, often following major lava dome collapses. We use ultraviolet (UV) and infrared (IR) satellite measurements to quantify sulfur dioxide (SO2) released by explosive degassing, which is not captured by routine ground‐based and airborne gas monitoring. We find a total explosive SO2 release of ∼0.5 Tg, which represents ∼6% of total SO2 emissions from SHV since July 1995. The majority of this SO2 (∼0.4 Tg) was vented following the most voluminous SHV dome collapses in July 2003 and May 2006. Based on our analysis, we suggest that the SO2 burden measured following explosive disruption of lava domes depends on several factors, including the instantaneous lava effusion rate, dome height above the conduit, and the vertical component of directed explosions. Space‐based SO2 measurements merit inclusion in routine gas monitoring at SHV and other dome‐forming volcanoes.