The atmosphere that allows our planet to sustain life formed from gases emitted by volcanoes early in Earth’s history. These volatile elements are constantly recycled back into the deep Earth at subduction zones, where tectonic plates sink into the mantle. During this process the sinking plate was subjected to increasing heat and pressure, and releases volatiles. These volatiles, once added to the mantle, induce melting and fuel volcanic explosions, completing the cycle. While this depiction of the earth’s giant recycling factory was well established conceptually, they do not know how efficient it is. They can estimate how much goes in, but have little idea what proportion was released back to the atmosphere, and what proportion remains trapped at depth. This question was crucial if they want to understand how our atmosphere formed and our planet became able to sustain life. In the present-day context, characterizing how much gas comes out of the giant recycling factory was also key to understanding volcanic effects on climate, volcanic emissions being significant – but poorly constrained – parameters in current climate models..
Their team of early career volcanologists was conducting expeditions to the South American Andes. Their objective was to provide the first accurate and large-scale estimate of the flux of volatile species (H2O, H2, CO2, CO, SO2, H2S, HCl, HF, and more) emitted by volcanoes of the Nazca subduction zone. The journey was taking us across half a continent, from the giant volcanoes of Ecuador through the altiplanoes of Peru and to the Southern tip of Chile, traveling on some of the Earth’s highest roads, and climbing some of the Earth’s tallest volcanoes.
