First characterization of Gamkonora gas emission, North Maluku, East Indonesia

Abstract

Gamkonora is an active volcano capable of intense manifestations that regularly forced thousands of inhabitants to flee their villages. The most extreme eruption, in 1673, was a VEI 5 event that induced pitch-dark environment over the region. Paradoxically, little is known about Gamkonora volcano and here we present the first gas measurement results obtained in September 2018 using a MultiGAS and a scanning DOAS. Results highlight a relatively small but magmatic gas with a CO2/S-T of 3.5, in the range of high-temperature gas emissions from Indonesian volcanoes and H2O/SO2, CO2/SO2, H2S/SO2, and H-2/SO2 ratios of 135, 5.6, 0.6, and 0.2, respectively. The daily gas emission budget corresponds to 129 t, 13 t, 3.4 t, 1.1 t, and 0.03 t for H2O, CO2, SO2, H2S, and H-2, respectively. Bulk rock analyses indicate a basaltic andesite to andesite source beneath Gamkonora